Blue Screen of Death

A **stop error**, better known as a **Blue Screen of Death** (also known as a **blue screen** or **BSoD**) is an error screen displayed on a Windows computer system after a fatal system error, also known as a system crash: when the operating system reaches a condition where it can no longer operate safely.

## History

BSoDs have been present in Windows NT 3.1 (the first version of the Windows NT family, released in 1993) and all Windows operating systems released afterwards. (See History of Microsoft Windows.) BSoDs can be caused by poorly written device drivers or malfunctioning hardware, 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. Because of the instability and lack of memory protection in Windows 9x, BSoDs were much more common.[*citation needed*]

### Incorrect attribution

On 4 September 2014, several online journals, including *Business Insider*,[1] *DailyTech*,[2] *Engadget*,[3] *Gizmodo*,[4] *Lifehacker*,[5] *Neowin*,[6]*Softpedia*,[7] *TechSpot*,[8] *The Register*,[9] and *The Verge*[10] attributed the creation of the Blue Screen of Death to Microsoft's former CEO Steve Ballmer while citing a source that does not say so: An article by Raymond Chen, a Microsoft employee, titled "Who wrote the text for the Ctrl+Alt+Del dialog in Windows 3.1?"[11] The article was about the creation of the first rudimentary task manager in Windows 3.x, which shared visual similarities with a BSoD.[11] In a follow up on 9 September 2014, Raymond Chen complained about this widespread mistake, claimed responsibility for revising the BSoD in Windows 95 and panned BGR.com for having "entirely fabricated a scenario and posited it as real".[12] Engadget later updated its article to correct the mistake.[3]

## Format

Until Windows Server 2012, BSoDs showed silver text on a navy blue background with information about current memory values and register values. Windows Server 2012, Windows 8 and Windows 10 use a cerulean background instead.

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 BSoDs use the Lucida Consolefont while the Windows Vista and 7 BSoD uses the Consolas font. Windows 8, Windows Server 2012 use Segoe UI and attempt to render the BSoD at native resolution, otherwise defaulting to 640x480. Windows 10 uses the same format as Windows 8 and up, 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.[13] Starting in December 2016, Windows Insider builds of Windows 10feature a green error screen.[14][15]

## Windows NT

In Windows NT family of operating systems, the blue screen of death (officially known as a **stop error** and 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 modeencounters 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 data that has not yet been saved to the hard drive.

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.[16]