cjturner

If explorer is started from the GUI in XP, the windows 'parent' process handles it. However, if you start one from a batch file or a CMD window, another instance appears. Something wants its own copy. Do you have a VPN installled, by any chance? More info might be available if you use Sysinternals Procexp.exe.

Successful boot in safe mode? See if problem is related to SCSIport 'STOP' problem. KB904374 http://support.microsoft.com/kb/904374/