Blue screen of death

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The blue screen of death in Windows 11 builds prior to 22000.348, which was black except for the QR code

A blue screen of death (BSoD), officially known as a stop error or blue screen error,[1] is an error screen that the Windows operating system displays in the event of a fatal system error. It indicates a system crash, in which the operating system has reached a critical condition where it can no longer operate safely, e.g., hardware failure or a unexpected termination of a crucial process.


Blue screen on Windows 1.01
The "Incorrect DOS Version" screen on Windows 1.01, featuring random characters[2]
External video
YouTube logo
The "Incorrect Dos Version" screen on Windows 1.01, featuring random characters
video icon Windows 1.0 BSOD (Incorrect DOS Version): Short version, showing a failed Windows startup
video icon Windows 1.01 Blue Screen of Death: Long version, showing installation DOS 6, Windows 1.01, and the failed startup of Windows 1.01

Blue error screens have been around since the beta version of Windows 1.0; if Windows found a newer DOS version than it expected, it would generate a blue screen with white text saying "Incorrect DOS version", before starting normally.[2] In the final release (version 1.01), however, this screen would print garbage output instead.[2] This screen was the outcome of a bug in the Windows logo code.[2] It was not a crash screen, either; when the system did crash, it would either lock up or exit to DOS.

Windows 3.0 uses a text-mode screen for displaying important system messages, usually from digital device drivers in 386 Enhanced Mode or other situations where a program could not run. Windows 3.1 changed the color of this screen from black to blue. Windows 3.1 would also displays a blue screen when the user presses the Ctrl+Alt+Delete key combination while no programs were unresponsive. As with it predecessors, Windows 3.x exits to DOS if an error condition is severe enough.

The original BSoD from Windows NT

The first blue screen of death appeared in Windows NT 3.1[3] (the first version of the Windows NT family, released in 1993) and all Windows operating systems released afterwards. In its earliest version, the error started with ***STOP:. Hence, it became known as a "stop error."

BSoDs can be caused by poorly written device drivers or malfunctioning hardware,[4] such as faulty memory, power supply issues, overheating of components, or hardware running beyond its specification limits. In the Windows 9x era, incompatible DLLs or bugs in the operating system kernel could also cause BSoDs.[5] Because of the instability and lack of memory protection in Windows 9x, BSoDs were much more common.

Incorrect attribution[edit]

On September 4, 2014, several online journals, including Business Insider,[6] DailyTech,[7] Engadget,[8] Gizmodo,[9] Lifehacker,[10] Neowin,[11] Softpedia,[12] TechSpot,[13] The Register,[14] and The Verge[15] incorrectly attributed the creation of the Blue Screen of Death to Steve Ballmer, Microsoft's former CEO, citing an article by Microsoft employee Raymond Chen, entitled "Who wrote the text for the Ctrl+Alt+Del dialog [sic] in Windows 3.1?".[16] The article focused on the creation of the first rudimentary task manager in Windows 3.x, which shared visual similarities with a BSoD.[16] In a follow-up on September 9, 2014, Raymond Chen complained about this widespread mistake, claimed responsibility for revising the BSoD in Windows 95 and panned for having "entirely fabricated a scenario and posited it as real".[17] Engadget later updated its article to correct the mistake.[8]


Until Windows 8 and Windows Server 2012, BSoDs showed silver text on a royal blue background with information about current memory values and register values. Windows Server 2012, Windows 8 and Windows 10 use a cerulean background. Windows 11 builds from 22000.348 onwards use a dark blue background,[18] and prior builds used a black background.[19]

Windows 95, 98 and ME BSoDs use 80×25 text mode. BSoDs in the Windows NT family use 80×50 text mode on a 720×400 screen. Windows XP, Vista and 7 BSoDs use the Lucida Console font. Windows 8, Windows Server 2012 use Segoe UI and render the BSoD contents at the boot framebuffer resolution, over top of the active resolution, with UEFI machines generally using the highest Graphics Output Protocol mode available, and with legacy BIOS machines either using 1024x768 (with the contents being squished due to the monitor being presumed to be widescreen) or the highest VESA BIOS Extensions mode available (should the BCDEdit parameter 'highestmode' be enabled[20]). Windows 10 versions 1607 onwards uses the same format as Windows 8, but has a QR code which leads to a Microsoft survey about how the blue screen was caused.

Despite the "blue screen" name, in Windows 9x, the color of the message could be customized by the user.[21] As of December 2016, Windows Insider builds of Windows 10, Windows 11, and Windows Server feature a dark green background instead of a blue one.[22][23][19]

Windows NT[edit]

The Blue Screen of Death in Windows XP, Windows Vista and Windows 7
The Blue screen of death on Windows 8 and 8.1.
The Blue Screen of Death in Windows 8, which includes a sad emoticon and an Internet search for quick troubleshooting
The Blue Screen of Death in Windows 10 versions 1607–1909, which includes a sad emoticon and a QR code for quick troubleshooting

In the Windows NT family of operating systems, the blue screen of death (referred to as "bug check" in the Windows software development kit and driver development kit documentation) occurs when the kernel or a driver running in kernel mode encounters an error from which it cannot recover. This is usually caused by an illegal operation being performed. The only safe action the operating system can take in this situation is to restart the computer. As a result, data may be lost, as users are not given an opportunity to save it.

The text on the error screen contains the code of the error and its symbolic name (e.g. "0x0000001E, KMODE_EXCEPTION_NOT_HANDLED") along with four error-dependent values in parentheses that are there to help software engineers fix the problem that occurred. Depending on the error code, it may display the address where the problem occurred, along with the driver which is loaded at that address. Under Windows NT, the second and third sections of the screen may contain information on all loaded drivers and a stack dump, respectively. The driver information is in three columns; the first lists the base address of the driver, the second lists the driver's creation date (as a Unix timestamp), and the third lists the name of the driver.[24]By default, Windows will create a memory dump file when a stop error occurs. Depending on the OS version, there may be several formats this can be saved in, ranging from a 64kB "minidump" (introduced in Windows 2000) to a "complete dump" which is effectively a copy of the entire contents of physical memory (RAM). The resulting memory dump file may be debugged later, using a kernel debugger. For Windows WinDBG or KD debuggers from Debugging Tools for Windows are used.[25] A debugger is necessary to obtain a stack trace, and may be required to ascertain the true cause of the problem; as the information on-screen is limited and thus possibly misleading, it may hide the true source of the error. By default, Windows XP is configured to save only a 64kB minidump when it encounters a stop error, and to then automatically reboot the computer. Because this process happens very quickly, the blue screen may be seen only for an instant or not at all. Users have sometimes noted this as a random reboot rather than a traditional stop error, and are only aware of an issue after Windows reboots and displays a notification that it has recovered from a serious error. This happens only when the computer has a function called "Auto Restart" enabled, which can be disabled in the Control Panel which in turn shows the stop error.

Microsoft Windows can also be configured to send live debugging information to a kernel debugger running on a separate computer. If a stop error is encountered while a live kernel debugger is attached to the system, Windows will halt execution and cause the debugger to break in, rather than displaying the BSoD. The debugger can then be used to examine the contents of memory and determine the source of the problem.

A BSoD can also be caused by a critical boot loader error, where the operating system is unable to access the boot partition due to incorrect storage drivers, a damaged file system or similar problems. The error code in this situation is STOP 0x0000007B (INACCESSIBLE_BOOT_DEVICE).[26] In such cases, there is no memory dump saved. Since the system is unable to boot from the hard drive in this situation, correction of the problem often requires using the repair tools found on the Windows installation disc.


Before Windows Server 2012, each BSoD displayed an error name in uppercase (e.g. APC_INDEX_MISMATCH), a hexadecimal error number (e.g. 0x00000001) and four parameters. The last two are shown together in the following format:[27]

error code (parameter 1, parameter 2, parameter 3, parameter 4) error name

Depending on the error number and its nature, all, some, or even none of the parameters contain data pertaining to what went wrong, and/or where it happened. In addition, the error screens showed four paragraphs of general explanation and advice and may have included other technical data such the file name of the culprit and memory addresses.

With the release of Windows Server 2012, the BSoD was changed, removing all of the above in favor of the error name, and a concise description. Windows 8 added a sad-emoticon as well. The hexadecimal error code and parameters can still be found in the Windows Event Log or in memory dumps. Since Windows 10 Build 14393, the screen features a QR code for quick troubleshooting. Windows 10 Build 19041 slightly changed the text from "Your PC ran into a problem" to "Your device ran into a problem".

Windows 9x[edit]

A blue screen of death, as appears on Windows 9x

The blue screen of death frequently occurs in Microsoft's home desktop operating systems Windows 95, 98, and ME. In these operating systems, the BSoD is the main way for virtual device drivers to report errors to the user. It is internally referred to by the name of "_VWIN32_FaultPopup". A Windows 9x BSoD gives the user the option either to restart the computer or to continue using Windows, unlike a BSoD on a Windows NT system, which prevents the user from using the computer until it has been restarted.

The most common BSoD is an 80×25 screen which is the operating system's way of reporting an interrupt caused by a processor exception; it is a more serious form of the general protection fault dialog boxes. The memory address of the error is given and the error type is a hexadecimal number from 00 to 11 (0 to 17 decimal). The error codes are as follows:[28]

  • 00: Division fault
  • 01: Startup Error
  • 02: Non-Maskable Interrupt
  • 03: Shutdown Error
  • 04: Overflow Trap
  • 05: Bounds Check Fault
  • 06: Invalid Opcode Fault
  • 07: "Coprocessor Not Available" Fault
  • 08: Double Fault
  • 09: Coprocessor Segment Overrun
  • 0A: Invalid Task State Segment Fault
  • 0B: Not Present Fault
  • 0C: Stack Fault
  • 0D: General Protection Fault
  • 0E: Page Fault
  • 0F: Error Message Limit Exceed
  • 10: Coprocessor Error Fault
  • 11: Alignment Check Fault

Reasons for BSoDs include:

  • Problems that occur with incompatible versions of DLLs: Windows loads these DLLs into memory when they are needed by application programs; if versions are changed, the next time an application loads the DLL it may be different from what the application expects. These incompatibilities increase over time as more new software is installed, and is one of the main reasons why a freshly installed copy of Windows is more stable than an "old" one.
  • Faulty or poorly written device drivers
  • Hardware incompatibilities

Damaged hardware may also cause a BSoD.

In Windows 95 and 98, a BSoD occurs when the system attempts to access the file "c:\con\con","c:\aux\aux",or"c:\prn\prn" on the hard drive. This could be inserted on a website to crash visitors' machines. On 16 March 2000, Microsoft released a security update to resolve this issue.[29]

One famous instance of a Windows 9x BSoD occurred during a presentation of a Windows 98 beta given by Bill Gates at COMDEX on April 20, 1998: The demo PC crashed with a BSoD when his assistant, Chris Capossela, connected a scanner to the PC to demonstrate Windows 98's support for Plug and Play devices. This event brought thunderous applause from the crowd and Gates replied (after a nervous pause): "That must be why we're not shipping Windows 98 yet."[30]

Windows CE[edit]

Windows CE 5.0 Blue Screen of Death

The simplest version of the blue screen occurs in Windows CE (except in Pocket PC 2000 and Pocket PC 2002). The blue screen in Windows CE 3.0 is similar to the one in Windows NT.


Similar screens[edit]

The Red Screen of Death in a post-reset Windows Longhorn build

Stop errors are comparable to kernel panics in macOS, Linux, and other Unix-like systems, and to bugchecks in OpenVMS. Windows 3.1, like some versions of macOS, displays a Black Screen of Death instead of a blue one.[17][31] Windows 98 displays a red error screen raised by the Advanced Configuration and Power Interface (ACPI) when the host computer's BIOS encounters a problem.[32] The bootloader of the first beta version of Windows Vista also displays a red error screen in the event of a boot failure.[33][34][35] The Xbox One has a Green Screen of Death instead of the blue one.[citation needed]

As mentioned earlier, the insider builds of Windows Server 2016 and later, Windows 10, and Windows 11 display a green screen.[22][23][19]

See also[edit]


  1. ^ "Troubleshoot blue screen errors". Support. Microsoft. 10 April 2019. Archived from the original on 20 September 2020.
  2. ^ a b c d "Why does Windows 1.01 crash at the splash screen?". Retro Computing. 30 August 2021. In the final release of Windows, these detailed messages were hastily removed. The code that would print them, however, was not, and this is what produces the garbage output.
  3. ^ Chen, Raymond (September 26, 2017). "Who implemented the Windows NT blue screen of death?". Microsoft. Retrieved October 1, 2021.
  4. ^ Wilson, Michelle (July 25, 2019). "What is the Blue Screen of Death in Windows 10 and How to Fix it?". HP. Retrieved October 1, 2021.
  5. ^ Cepero, Robert (May 17, 2019). "Blue Screen of Death: Causes and Fixes". Bleuwire. Retrieved October 1, 2021.
  6. ^ Smith, Dave (4 September 2014). "Steve Ballmer Wrote The Blue Screen Of Death". Business Insider. Business Insider Inc. Archived from the original on 8 September 2014. Retrieved 10 September 2014.
  7. ^ Mick, Jason (4 September 2014). "Microsoft Exec Reveals Steve Ballmer Created Original Blue Screen of Death Message". Daily Tech. DailyTech LLC. Archived from the original on 2015-08-20. Retrieved 10 September 2014.
  8. ^ a b Fingas, Jon (4 September 2014). "Steve Ballmer wrote Windows' first Ctrl-Alt-Delete message (updated)". Engadget. AOL. Archived from the original on 9 September 2014. Retrieved 10 September 2014.
  9. ^ Condliffe, Jamie (4 September 2014). "Steve Ballmer Wrote the Blue Screen of Death". Gizmodo. Gizmodo Media Group. Archived from the original on 11 September 2014. Retrieved 10 September 2014.
  10. ^ Kidman, Alex (5 September 2014). "Steve Ballmer Wrote The BSOD, So Stop Slacking Off". Lifehacker. Allure Media. Archived from the original on 10 September 2014. Retrieved 10 September 2014.
  11. ^ Sams, Brad (4 September 2014). "Steve Ballmer wrote the BSOD text". Neowin. Neowin LLC. Archived from the original on 8 September 2014. Retrieved 10 September 2014.
  12. ^ Popa, Bogdan (4 September 2014). "Steve Ballmer Himself Created the First Blue Screen of Death Text". Softpedia. SoftNews SRL. Archived from the original on 10 September 2014. Retrieved 10 September 2014.
  13. ^ Schiesser, Tim (4 September 2014). "The original Blue Screen of Death was written by Steve Ballmer". TechSpot. Archived from the original on 10 September 2014. Retrieved 10 September 2014.
  14. ^ Sharwood, Simon (4 September 2014). "Ballmer PERSONALLY wrote Windows' Blue Screen of Death text". The Register. Archived from the original on 8 September 2014. Retrieved 10 September 2014.
  15. ^ Warren, Tom (4 September 2014). "Steve Ballmer wrote the Blue Screen of Death message". The Verge. Vox Media. Archived from the original on 7 September 2014. Retrieved 10 September 2014.
  16. ^ a b Chen, Raymond (2 September 2014). "Who wrote the text for the Ctrl+Alt+Del dialog in Windows 3.1?". The Old New Thing. Microsoft. Archived from the original on 15 November 2020. Retrieved 13 November 2020.
  17. ^ a b Chen, Raymond (9 September 2014). "Steve Ballmer did not write the text for the blue screen of death". The Old New Thing. Microsoft. Archived from the original on 25 October 2020. Retrieved 13 November 2020.
  18. ^ Klotz, Aaron. "Windows 11 Update Makes BSOD Blue Again and Fixes Major File Explorer Bugs". Tom's Hardware. Retrieved 24 November 2021.
  19. ^ a b c Warren, Tom (1 July 2021). "Microsoft's Blue Screen of Death is changing to black in Windows 11". The Verge. Vox Media. Retrieved 2 July 2021. While Microsoft is switching to a Black Screen of Death in Windows 11, the screen is identical to the one found in Windows 10 otherwise. The sad face remains, as does the stop code and crash dump. The current preview of Windows 11 includes a green BSOD, a color that Microsoft has been using for Windows Insider builds since 2016.
  20. ^ EliotSeattle. "BCDEdit /set - Windows drivers". Archived from the original on 2020-12-25. Retrieved 2020-12-19.
  21. ^ Scott Seely (2000). Windows Shell Programming. Prentice Hall PTR. pp. 232–233. ISBN 9780130254962. BSOD stands for Blue Screen Of Death. One can customize the colors of this screen by setting a couple of variables in the 386Enh section of SYSTEM.INI: MessageTextColor and MessageBackColor. The user can only customize the BSOD under Windows 3.1, 95, and 98. These changes do not work under the Windows NT variants.
  22. ^ a b "Behold the Windows 10 GSOD -- Green Screen of Death". BetaNews. 2016-12-29. Archived from the original on 2017-01-12. Retrieved 2017-01-13.
  23. ^ a b Warren, Tom (December 29, 2016). "Windows 10 testers will now get a Green Screen of Death". The Verge. Vox Media. Archived from the original on 1 January 2017. Retrieved 1 February 2017.
  24. ^ Microsoft Windows NT Workstation Resource Kit (1st ed.). Redmond, WA: Microsoft Press. 29 October 1996. ISBN 1-57231-343-9.
  25. ^ DOMARS. "Getting Started with WinDbg (Kernel-Mode)". Archived from the original on 14 March 2016. Retrieved 15 June 2018.
  26. ^ "Stop error code 0x0000007B (INACCESSIBLE_BOOT_DEVICE)". 2018-04-17. Archived from the original on 2021-03-28. Retrieved 2020-01-16.
  27. ^ "STOP: 0x00000001 (parameter, parameter, parameter, parameter) APC_INDEX_MIS". Archived from the original on 15 June 2018. Retrieved 15 June 2018.
  28. ^ "What Are Fatal Exception Errors". Support. Microsoft. 19 January 2007. Archived from the original on 23 August 2003. Retrieved 16 October 2013.
  29. ^ Microsoft Corporation (2000). "Patch Available for "DOS Device in Path Name" Vulnerability". TechNet. Microsoft. Archived from the original on 30 August 2011. Retrieved 4 March 2006.
  30. ^ Garmon, Jay (12 April 2007). "Video: Bill Gates, meet the Blue Screen of Death". TechRepublic. CBS Interactive. Archived from the original on 20 December 2013. Retrieved 20 December 2013.
  31. ^ David W. Martin (6 August 2011). "Black Screen Of Death Plagues Some Mac Users After Lion Update". Archived from the original on 28 August 2018. Retrieved 27 August 2018.
  32. ^ "Advanced Configuration and Power Interface Errors on Red Screen". Support (1.3 ed.). Microsoft. 10 January 2015. Archived from the original on 25 July 2015.
  33. ^ Kaplan, Michael (7 May 2005). "Longhorn on Virtual PC 2004". Sorting it all Out. Microsoft. Archived from the original on 3 January 2013.
  34. ^ Best, Jo (11 May 2005). "Red screen of death?". CNET. CBS Interactive. Archived from the original on 9 August 2011. Retrieved 9 September 2013.
  35. ^ Farrell, Nick (3 June 2005). "Microsoft sees red over blue screen of death". The Inquirer. Incisive Media. Archived from the original on 25 August 2009. Retrieved 9 September 2013.CS1 maint: unfit URL (link)

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