What Causes a Computer Monitor to Turn Blue?

By Sam N. Austin

The display on a computer monitor turns blue and displays only white text with technical information when the computer crashes in a particular way. This type of crash, a blue screen crash, happens when a computer's operating system (OS) encounters a fatal error software or driver conflict and cannot recover.

A blue screen indicates a fatal computer error.
i "Blue Screen of Death - vertical" is Copyrighted by Flickr user: nodomain1 (Joe C) under the Creative Commons Attribution license.


Computer blue screens emerged on personal computers with the introduction of the earliest operating systems. Computer users began to encounter blue screens with Microsoft Windows 1.0 as early as 1985. As Windows operating systems became more widespread, in particular Windows XP in 2001, blue screens became part of the computer vernacular in the phrase BSOD, or blue screen of death.


The computer blue screen indicates that a computer's operating system has encountered a problem from which it cannot recover and that prevents it from continuing to operate. Unlike other types of OS conflicts, which the end-user can resolve by means such as closing a conflicting program or removing a conflicting piece of hardware, the blue screen cannot be resolved. Therefore, work that was in progress, such as work in a spreadsheet or word processor, is lost when a blue screen occurs.


Blue screens are most closely associated with Windows operating systems. However, blue screens can occur with any operating system that uses a particular class of microprocessor, x86 processors. As a result, users may encounter Mac blue screens as well as Windows blue screens. The parallel phenomenon more common to Macs is the Sad Mac, the image of a Mac computer with the appearance of a sad face, indicating that the Mac computer has stopped operating and cannot continue.


Because the blue screen occurs when a computer's OS fails, any work that is in progress on the computer when the blue screen appears will be lost. For example, if a user has a spreadsheet or word processing document open, but has not saved the document, any changes the user has made to the document since the last save will be irretrievably lost. In addition, software applications that require a specific shut-down process to close correctly may become damaged because they cannot be closed correctly.


When a user encounters a blue screen, the only remedy is to turn the blue-screened computer off physically, then restart it. If the blue screen occurs frequently, the user can write down the text displayed in the blue screen and provide it to a qualified professional to see if it is possible to prevent the conflict from recurring.