Apparently this is a rareissue. However, it did cost me four days of mucking with my laptop to fix.
The Red Gate ANTS uninstaller doesn’t always remove it’s services, even though thefiles are gone. For some reason, this causes Vista to reboot almost immediately aftergetting to the login screen. The fix is simple:
SCDELETE “ANTSPerformance Profiler 4 Service“ SCDELETE “ANTSMemory Profiler 4 Service“
A couple of commands from the command prompt will clear the services. Try using ‘lastknown configuration’ to get you to that command prompt. Safe Mode didn’t work forme.