What is "blue screen of death"

n. (context computing English) an (l/en: error screen) displayed by some (l/en operating system operating systems), especially http://en.wikipedia.org/wiki/Microsoft%20Windows, after encountering an unrecoverable (l/en: error) which causes the system to shut down.

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.