Black Screen of Death definition, from Internet Connection, Inc.

[prob.: related to the Floating Head of Death in a famous Far Side cartoon.] A failure mode of Microsloth Windows. On an attempt to launch a DOS box, a networked Windows system not uncommonly blanks the screen and locks up the PC so hard that it requires a cold boot to recover. This unhappy phenomenon is known as The Black Screen of Death. See also Blue Screen of Death, which has become rather more common.