XP PRO LOCKUP

WinXP Pro
2.8mHz
1024 RAM
160G HDD – 106G free
Nvidia 256MB GeForce 6600 video

When I’m in the middle of a game(s) my computer locks up solid. I’ve installed new
video cards with negative results. The temperatures are 96 – 104F. I’m clueless and need some HELP!

Thank you.