Microsoft Windows

Mi¢ro$oft Window$

Window$ logo
File:Window$ xp desktop.PNG A typical Window$ XP desktop.
Developer	Mi¢ro$oft Corporation
OS family	MS-DOS-based, Window$ NT, Window$ 9x, Window$ CE
Working state	Current
License	MS-EULA
Official website	Mi¢ro$oft Window$

Mi¢ro$oft Window$ is a family of operating systems by Mi¢ro$oft for use on personal computers, although versions of Window$ designed for servers, embedded devices, and other platforms also exist. Mi¢ro$oft first introduced an operating environment named Window$ in November 1985 as an add-on to MS-DOS in response to the growing trend of graphical user interfaces popularized by the Apple Macintosh. Mi¢ro$oft Window$ eventually came to dominate the world's personal computer market. At the 2004 IDC Directions conference, IDC Vice President Avneesh Saxena stated that Window$ had approximately 90% of the client operating system market.

Mi¢ro$oft Window$ versions

See also: List of Mi¢ro$oft Window$ versions

The term Window$ collectively describes any or all of several generations of Mi¢ro$oft operating system products. These products are generally categorized as follows:

16-bit operating environments

File:Window$ 1.0.jpg

The box art of Window$ 1.0, the first version Mi¢ro$oft released to the public. The same box art was used in other versions, such as 1.01.

The early versions of Window$ were often thought of as just graphical user interfaces or desktops, mostly because they were started from MS-DOS and used it for file system services. However even the earliest 16-bit Window$ versions already assumed many typical operating system functions, notably having their own executable file format and providing their own device drivers (timer, graphics, printer, mouse, keyboard and sound) for applications. Unlike DOS, Window$ allowed users to execute multiple graphical applications at the same time, through co-operative multitasking. Finally, Window$ implemented an elaborate, segment-based, software virtual memory scheme which allowed it to run applications larger than available memory: code segments and resources were swapped in and thrown away when memory became scarce, and data segments moved in memory when a given application had relinquished processor control, typically waiting for user input. Examples include Window$ 1.0 (1985) and Window$ 2.0 (1987) and its close relative Window$/286.

Hybrid 16/32-bit operating environments

Window$/386 introduced a 32-bit protected mode kernel and virtual machine monitor. For the duration of a Window$ session, it created one or more virtual 8086 environments and provided device virtualization for the video card, keyboard, mouse, timer and interrupt controller inside each of them. The user-visible consequence was that it became possible to preemptively multitask multiple MS-DOS environments in separate Window$ (graphical applications required switching the window to full screen mode). Window$ applications were still multi-tasked cooperatively inside one of such real-mode environments.

Window$ 3.0 (1990) and Window$ 3.1 (1992) perfected the design, mostly thanks to virtual memory and loadable virtual device drivers (VxDs) which allowed them to share arbitrary devices between multitasked DOS Window$. Because of this, Window$ applications could now run in 16-bit protected mode (when Window$ was running in Standard or 386 Enhanced Mode), which gave them access to several megabytes of memory and removed the obligation to participate in the software virtual memory scheme. They still ran inside the same address space, where the segmented memory provided a degree of protection, and multi-tasked cooperatively. For Window$ 3.0 Mi¢ro$oft also rewrote critical operations from C into assembly, making this release faster and less memory-hungry than its predecessors.

Hybrid 16/32-bit operating systems

File:Mi¢ro$oft Window$ Logo from 1992 to 2000.png

The Window$ logo that was used from 1992 to 2000.

With the introduction of 32-bit File Access in Window$ for Workgroups 3.11, Window$ could finally stop relying on DOS for file management. Leveraging this, Window$ 95 introduced Long File Names, reducing the 8.3 DOS to the role of a boot loader. MS-DOS was now bundled with Window$; this notably made it (partially) aware of long file names when its utilities were run from within Window$, but angered the competition. The most important novelty was the possibility of running 32-bit multi-threaded preemptively multitasked graphical programs. Alas, the necessity of keeping compatibility with 16-bit programs meant the GUI components were still 16-bit only and not fully reentrant, which resulted in reduced performance and stability.

There were three releases of Window$ 95 (the first in 1995, then subsequent bug-fix versions in 1996 and 1997, only released to OEMs, which added extra features such as FAT32 support). Mi¢ro$oft's next OS was Window$ 98; there were two versions of this (the first in 1998 and the second, named "Window$ 98 Second Edition", in 1999). In 2000, Mi¢ro$oft released Window$ Me (Me standing for Millennium Edition), which used the same core as Window$ 98 but adopted the visual appearance of Window$ 2000, as well as a new feature called System Restore, allowing the user to set the computer's settings back to an earlier date. It was not a very well received implementation, and many user problems occurred. Me was considered a stopgap to the day both product lines would be seamlessly merged. Mi¢ro$oft left little time for Window$ Me to become popular before announcing their next version of Window$ which would be called XP.

32-bit operating systems

This family of Window$ systems was designed and marketed for higher-reliability business use, and was unencumbered by any DOS heritage. The first release was Window$ NT 3.1 (1993, numbered "3.1" to match the Window$ version and to one-up OS/2 2.1, IBM's flagship OS co-developed by Mi¢ro$oft and Window$ NT's main competitor at the time), which was followed by NT 3.5 (1994), NT 3.51 (1995), and NT 4.0 (1996); the latter implemented the Window$ 95 user interface. Mi¢ro$oft then moved to combine their consumer and business operating systems. Their first attempt, Window$ 2000, failed to meet their goals, and was released as a business system. The home consumer edition of Window$ 2000, codenamed "Window$ Neptune", ceased development and Mi¢ro$oft released Window$ Me in its place. Eventually "Neptune" was merged into their new project, Whistler, which later became Window$ XP. Since then, a new business system, Window$ Server 2003, has expanded the top end of the range, and the forthcoming Window$ Vista will complete it. Window$ CE, Mi¢ro$oft's offering in the mobile and embedded markets, is also a true 32-bit operating system.

64-bit operating systems

Window$ NT included support for several different platforms before the x86-based personal computer became dominant in the professional world. Versions of NT from 3.1 to 4.0 supported DEC Alpha and MIPS R4000, which were 64-bit processors, although the operating system treated them as 32-bit processors.

With the introduction of the IA-64 architecture (or Itanium, after the processors that implement it), and later the AMD64 architecture (also known as x86-64, x64 by Mi¢ro$oft, and implemented by Intel as EM64T), Mi¢ro$oft released new versions of its more contemporary operating systems to support them. The modern 64-bit Window$ family comprises Window$ XP 64-bit Edition for IA-64 systems, Window$ XP Professional x64 Edition for AMD64 systems, and Window$ Server 2003, in versions for both IA-64 and AMD64. The AMD64 versions of Window$ XP Professional and Server 2003 were released on April 25 2005, while the IA-64 versions were released at the same time as their mainstream x86 (32-bit) counterparts. Window$ Vista will be the first end-user version of Window$ that Mi¢ro$oft plans to release simultaneously in 32-bit and x64 editions.

Mi¢ro$oft Window$ history

Main article: History of Mi¢ro$oft Window$

File:Window$1screen.gif

A typical Window$ 1.0 desktop, running on Virtual PC on a Macintosh.

Mi¢ro$oft has taken two parallel routes in operating systems. One route has been the home user and the other has been the professional IT user. The dual route has generally led to the home versions with more "eye candy" and less functionality in networking and security and professional versions with less "eye candy" and better networking and security.

The first independent version of Mi¢ro$oft Window$, version 1.0, released in November 1985, lacked a degree of functionality and achieved little popularity. Window$ 1.0 did not provide a complete operating system; rather, it extended MS-DOS. Mi¢ro$oft Window$ version 2.0 was released in November, 1987 and was slightly more popular than its predecessor. Window$ 2.03 (release date January 1988) had changed the OS from tiled Window$ to overlapping Window$. The result of this change led to Apple Computer filing a suit against Mi¢ro$oft alleging infringement on Apple's copyrights.

File:Window$ 3.11 workspace.png

A typical Window$ 3.11 Workgroup desktop.

Mi¢ro$oft Window$ version 3.0, released in 1990, was the first Mi¢ro$oft Window$ version to achieve broad commercial success, selling 2 million copies in the first six months. It featured improvements to the user interface and to multitasking capabilities. In August 1995, Mi¢ro$oft released Window$ 95, which made further changes to the user interface and was the first Window$ version to utilize multitasking.

In July 1993, Mi¢ro$oft released Window$ NT based on IBM OS/2 technology (which Mi¢ro$oft had been co-developing for several years prior). NT was considered to be the professional OS. NT and the Window$ non-professional line would later be fused together to create Window$ XP.

The next in line was Mi¢ro$oft Window$ 98 released in June 1998. Substantially criticized for its slowness compared with Window$ 95, many of its basic problems were later rectified with the release of Window$ 98 Second Edition in 1999.

As part of its professional line, Mi¢ro$oft released Window$ 2000 in February 2000. The consumer version following Window$ 98 was Window$ Me (Window$ Millennium Edition). Released in September 2000, Window$ Me attempted to implement a number of new technologies for Mi¢ro$oft: most notably publicized was "Universal Plug and Play." However, the OS was substantially criticized for its lack of compatibility and stability.

The Window$ logo that was used from 2000 to 2001.

In October 2001, Mi¢ro$oft released Window$ XP, a version built on the Window$ NT kernel that also retained the consumer-oriented usability of Window$ 95 and its successors. It shipped in two distinct editions, "Home" and "Professional", the former lacking many of the superior security and networking features of the Professional edition. Additionally, the "Media Center" edition was released in 2003, with an emphasis on support for DVD and TV functionality including program recording and a remote control.

In April 2003, Window$ Server 2003 was introduced, replacing the Window$ 2000 line of server products with a number of new features and a strong focus on security; this was followed in December 2005 by Window$ Server 2003 R2.

Window$ Vista and Window$ Server "Longhorn", the successors to Window$ XP and Window$ Server 2003 respectively, are currently under development.

Interface

File:Window$ xp desktop.PNG

A typical Window$ XP desktop.

The most obvious feature of Window$ is a Window, or a container for other graphical objects. A Window in Mi¢ro$oft Window$ typically contains a status bar, title bar, minimize and maximize buttons, close button, and system menu (also called the Window$ menu or control menu). Another prominent feature since Window$ 95 and NT 4.0 is the desktop, which holds various icons that the user can double-click to open. The Start Button and Start Menu, attached to the taskbar and typically below the desktop, gives users access to installed programs and many of the other features of the operating system.

Due to these and other features, Window$ makes it possible to perform most common tasks, some quite complex, with very little computer knowledge. Window$ also comes with features to help the disabled through its accessibility options. Under Window$ XP, these features include the Narrator, Magnifier and contrast display mode.

Widespread Usage

Mi¢ro$oft Window$ is installed on the vast majority of personal computers. A July 2005 poll of Network Computing magazine readers found that 90% of their organizations used Mi¢ro$oft's desktop operating systems. It has achieved enormous market penetration due to the domination of MS-DOS in the early days of PC compatible computers (IBM PC, and various clones). It is also the primary platform for Mi¢ro$oft Office and most non-console computer games.

The widespread use of Mi¢ro$oft's operating system has benefited from not being tied to the success of one hardware manufacturer and from Mi¢ro$oft's willingness to license the operating system to manufacturers. This is in contrast with Apple Computer, which does not license Mac OS X to other manufacturers. However, the wide spectrum of possible hardware permutations with Mi¢ro$oft Window$ is also seen as a major source of computer problems because of hardware/software incompatibilities for consumers.

In the past, companies who wanted to be in the computer business had to create their own operating systems (such as the Amiga, BBC Micro or ZX Spectrum) or choose another OS; even an exclusive license with one vendor was significantly cheaper than developing and supporting a new operating system and software base.

Due to Mi¢ro$oft's extensive licensing agreements with many computer vendors, Window$ presently comes pre-installed on most computers as a bundled OEM version, making it the default choice for most of the market.

For some consumers, Window$ is the only valid option for a computing environment, or it is mandated by their workplace; additionally, an unfamiliarity with other operating systems results in a lack of desire to switch to other operating systems.

Finally, the large base of proprietary software available exclusively for the Window$ family of operating systems has become a large reason for the popularity of Window$, at least partly because many users do not realize that there are free, open source, and portable alternatives available. In recent years, many companies have been started with the sole intention of releasing Window$ software; the fact that there is already a large customer base in place is reason enough for such companies to spend their resources solely on Window$ software development. As a result, the fact that many companies are supporting Window$ exclusively is a self-reinforcing reason for customers to choose Window$.

Maintaining compatibility in a new release of Window$ with this large collection of software designed to run on older flavors of Window$ consumes a large part of the resources of the Window$ development team.

Security

File:Window$Security.png

The Window$ XP Security Center supplied in Service Pack 2.

Security has been a major weakness of Window$ for many years, and even Mi¢ro$oft itself has been the victim of security breaches. Due in some part to the widespread usage of Window$ on personal computers as well as a number of technical reasons there is a five fold greater amount of malware for Window$ than other operating systems such as Linux, Unix, Mac OS X, and FreeBSD. Window$ was originally designed for ease-of-use on a single-user PC without a network connection, and did not have security features built in from the outset. Window$ NT and its successors are designed for security (including on a network) and multi-user PCs, but was not designed for Internet security in mind as much since, when it was first developed, the Internet was less important. Combined with occasionally flawed code (such as buffer overflows), Window$ is a frequent target of worms and virus writers. Furthermore, until Window$ Server 2003 most versions of even Window$ NT were shipped with important security features disabled by default, and vulnerable (albeit useful) system services enabled by default. In June 2005, Bruce Schneier's Counterpane Internet Security reported that it had seen over 1,000 new viruses and worms in the previous six months.

Mi¢ro$oft publicly admitted their ongoing security problems shortly after the turn of the century and now claims to regard security as their number one priority. The much-needed Automatic Update came first with Window$ Me. As a result, Service Pack 2 for Window$ XP, as well as Window$ Server 2003, was installed by users more quickly than it might have been. Mi¢ro$oft releases security patches through its Window$ Update service approximately once a month (usually the second Tuesday of the month), although critical updates are made available at shorter intervals when necessary. In Window$ 2000 (SP3 and later), Window$ Me, Window$ XP and Window$ Server 2003, updates can be automatically downloaded and installed if the user selects to do so.

Window$ Defender

On January 6, 2005, Mi¢ro$oft released a beta version of Window$ AntiSpyware, based upon the previously released Giant AntiSpyware. On February 13, 2006, Window$ AntiSpyware became Window$ Defender with the release of beta 2. Window$ Defender is a freeware program designed to protect against spyware and other unwanted software.

Paul Thurrott's Supersite for Window$ gave Defender Beta 2 a stellar review; it received more middling reviews from other publications such as PCMagazine and CNet. Window$ 2000 and Window$ XP users can download the program for free from Mi¢ro$oft's web site, and Mi¢ro$oft has stated that Window$ Defender will ship as part of Window$ Vista.

Third-party analyses of Window$ security

A study conducted by Kevin Mitnick and marketing communications firm Avantgarde found that an unprotected and unpatched Window$ XP system lasted only 4 minutes on the Internet before it was compromised . The AOLNational Cyber Security Alliance Online Safety Study of October 2004 determined that 80% of Window$ users were infected by at least one spyware/adware product. Much documentation is available describing how to increase the security of Mi¢ro$oft Window$ products. Typical suggestions include deploying Mi¢ro$oft Window$ behind a hardware or software firewall, running anti-virus and anti-spyware software, and installing patches as they become available through Window$ Update.

Window$ emulation software

Emulation allows the use of some Window$ applications without using Mi¢ro$oft Window$. These include:

• Wine – (Wine Is Not an Emulator) an almost complete free software/open-source software implementation of the Window$ API, allowing one to run some Window$ applications on x86 Unix-based platforms, including Linux.
• CrossOver Office – a commercially packaged Wine with licensed fonts. Its developers are regular contributors to Wine, and focus on Wine running officially supported applications.
• Cedega (formerly known as WineX) – TransGaming Technologies' proprietary fork of Wine, which is designed specifically for running games written for Mi¢ro$oft Window$ under Linux.
• ReactOS – open-source operating system, aimed to be compatible with existing Window$ NT applications and drivers.
• Freedows and Alliance OS – a very ambitious project, and a subsequent spinoff, that tried to clone Window$ but withered away.
• Project David – ambitious and controversial project to fully emulate Window$ programs to run on other OSs.
• Win4Lin - Win4Lin is a virtual machine technology that allows Window$ to run as an application on Linux.
• Parallels Workstation - By Parallels Inc.
• Virtual PC - Virtual PC is an emulation suite for Apple Mac OS X, and a virtualization suite for Mi¢ro$oft Window$ operating systems. The software was originally written by Connectix, and was subsequently acquired by Mi¢ro$oft.
• Darwine - The Darwine project intends to port and develop WINE as well as other supporting tools that will allow Darwin and Mac OS X users to run Mi¢ro$oft Window$ Applications, and to provide a Win32 API compatibility at application source code level.

See also

• General
  • Comparison of operating systems
  • List of operating systems
  • Comparison of Window$ and Linux
• Further reading
  • Architecture of the Window$ NT operating system line
  • List of Mi¢ro$oft Window$ components
  • Mi¢ro$oft Window$ topics
  • Window$ Explorer
  • Window$ Genuine Advantage
  • Window$ Media

External links

Official

• Mi¢ro$oft's Official Window$ Website
• Official Promotional Website (Window$.com)
• Window$ history time line from Mi¢ro$oft

Tips and documentation

• How to run multiple versions of Window$ on one PC
• Tech-Recipes Window$ Guide - Listing of almost 500 Window$ Tutorials
• The Window$ Documentation Project (wiki)
• Securing Mi¢ro$oft Window$ (for Home and Small Business Users)
• Symantec Anti-Virus Research Center – excellent informational security resource, and Symantec are makers of Norton Anti-Virus (3rd party software sold separately)
• dotwhat? - File Extension Listing – a huge listing of file extensions and the programs that use them
• Window$ – tips and tricks for Window$ 98, ME, NT, 2000 and XP
• Window$ Support Script
• The Window$ Wiki
• Vernalex's Window$ Services Utility - An unofficial list of most Window$ services with detailed descriptions and recommended run states
• Window$ installation guide – Tips to set up and install Window$ XP

Programming Mi¢ro$oft Window$

• Mi¢ro$oft Development Network for programming Mi¢ro$oft Window$
• Window$ API tutorial in C++
• Programming Window$ in Assembly Language

Libraries

• RSWL, free Reliable Software C++ Window$ API library.

Reviews and evaluation

• Paul Thurrott's SuperSite for Window$ – an exhaustive evaluation of Mi¢ro$oft's products and technologies
• "Time to Live on the Network" – a security study by Kevin Mitnick and Avantgarde (PDF)
• Window$ XP: rough around the edges – an UI review of Window$ XP
• Frank Mahler's Interface Hall Of Shame(in German)
• AOL/National Cyber Security Alliance Online Safety Study (October 2004) (PDF)
• Interface Hall of Shame – an analysis of user interfaces with a focus on Window$

Other

• Window$ history – a Window$ history time line graph by Éric Lévénez (detailed, continually updated)
• GUIdebook: Window$ Gallery – a website dedicated to preserving and showcasing graphical user interfaces
• Window$ 20th Birthday