It's unlikely to be a virus, to be honest. I'd say you've done something by accident, like edit something with realising. Alas, I believe your best option here is to reformat. Alternatively, if you have a second hard-drive, try installing that, installing your OS to THAT hard-drive (fresh) and telling your BIOS to boot from that by default so you can identify the problemo.
If it is in fact drivers causing the issue...Then "Safe Mode" should work in theory. If there are multiple things wrong, then you may want to try repairing Windows with the Windows XP CD.
If all else fails, use the other Windows XP installation to access the other, copy all important information and format the drive for a fresh re-install.
Nothing else I can really suggest. Everything else will just consume time until you realise you actually have to format because everything else has failed.
Good luck.:cool:
"Three o'clock is always too late or too early for anything you want to do."