Gotta love Windows, eh?
I’m not positive, but there’s a few techniques at the following URL which *might* help:
Doesn’t address the cause of the issue, however. Sorry. Perhaps the registry got corrupted in the crash somehow (just a guess).
The system crash coupled with this behavior smacks of a virus. Reinstall the OS (or trash the PC since this question came out in ’04 and it’s now ’12).