BlueScreen
http://technet.microsoft.com/en-us/sysinternals/bb897558.aspx
BlueScreen
v3.2 (November 1, 2006)
This screen saver not only accurately simulates Blue Screens, but simulated reboots as well (complete with CHKDSK), and works on Windows NT 4, Windows 2000, Windows XP, Server 2003 and Windows 9x.