Running Windows XP Home on a Medion 1141 (don't know all the specs off hand). Running Antivir antivirus; zone alarm; spybot, and ad-aware. My computer was working relatively well (except for a few persistent pop-ups) until this morning when I went to turn it on. Turned it on, loaded up to the Windows screen where there is a sliding indicator bar and after a short time (about the average time it takes to load normally) instead of loading the selectable user names the computer would restart. After automatically restarting before windows would load the dialog of selecting how to start windows (start normally, in safe mode, last known good configuration) tried all the options and the same problem would occur.