A bug check, or bugcheck, is a computer term used to describe an action performed by an operating system (OS), usually a Microsoft Windows OS, when it encounters a very serious software or hardware problem. The OS halts all running processes, and either restarts the computer or displays a bug check screen with technical information about what caused the problem. Problems that cause this action are often serious enough that they can result in hardware failure, or extensive corruption of data, and the bug check is done to protect the computer system. Common problems that cause this computer action are incompatible or faulty hardware, like a damaged RAM memory unit or motherboard, hardware that is improperly connected inside the computer, or the installation of the wrong drivers. Other terms commonly used for this computer action are fatal system error, system crash, kernel error, and blue screen of death, so named because of the color of the screen displayed.
The screen that is sometimes displayed in connection with a bug check can provide information about how to resolve the issue. It often also provides a code. This code can be used as a reference by the computer user when attempting to locate the source of the problem and resolve it. Lists of such codes and explanations of their associated errors are available online and in computer documentation, such as a computer manual.
Detailed technical information about what causes a specific bug check is sometimes also provided by the OS in a so-called crash dump file, and can be accessed by the user to identify the problem and fix it. A computer user can also attempt to remedy the cause of a bug check by checking that all hardware is compatible with the OS, that the latest drivers for that hardware are installed, and that the BIOS, network cards, and SCSI controller are up to date. Using a so-called debugger, or a registry cleaner, can also help.
In cases where the bug check recurs and the cause of the problem cannot be located, it is advisable to contact a computer professional or repair facility. Continued use of the affected computer can cause hardware damage and data loss. The term bug check is most commonly used for the Windows OS, but similar actions are also performed by other operating systems, including UNIX and the Mac OS X. Kernel panic is the term used for this action when performed by a UNIX or UNIX-like OS.