Just finished scanning. NOTHING! Absolutely nothing. All it found first was 59 tracker cookies, which are nothing new, I mean even my adaware could have picked those up. But no viruses or anything were detected. Im so frustrated!
Have you tried restoring the PC back to a time before this problem started happing? When was the last time you did a clean reinstall of Windows XP Pro?
Edit, Have you also checked that the other fans are clean of dust? Also have you closed down any other programs in the backgorund that you dont neee running when you play games?