necko 0 Light Poster

Two months now, my Windows XP indicates "fatal error" and restarts my PC while McAfee is trying to do its weekly virus scan. "Fatal error" occurs when McAfee is scanning "HKU"s. I've asked McAfee and they advised me to uninstall and reinstall their program, which I did but nothing changed. Windows says they can't sort out the error and can't do anything about it.