No offense to Boogs, my Windows got boogered the other day. The last things I remember doing was running the MyDoom tool from Symantec and then created a WinNX unattended ISO. Then later at night when I got home to install my monitor I was suddenly logged into this Test account (with Admin rights) after starting up the PC. Upon examining Task Manager, I had 45 processes running (I normally max out at 32 processes) but only 10-12 of them were listed.
I tried running a virus scan (Zone Alarm antivirus) and that program seemed boogered too. I system restored successfully to the previous day's configuration but fearing that it was a virus behind this I just reformatted the drive to be safe.