Computer Freezes while playing games

[boondog]

New to this forum, but I really need some help. My computer is freezing is freezing when I try to play games ( Sims2, EQlive and EQ2) to name a few. It's getting really irratating. I have switched out my video card and tried different RAM cards. Also switched the sound card . Used conservitive settings. Tried checking for Mem Leaks. All drivers have been updated. Nothing seems to fix it. The CPU temp is running at about 45C, temp under a load is about 50C. The games usually freeze within 15 min of play and I have to hard rest the computer.

Specs are:
Proc 3.06 northwood 533FSB HT
MotherBoard SY4BGA
Mem 2x 256 PC2100 Samsong
GForce2mx400 video card
XP pro Service pack 2
500Watt Antec PSU

Any Help would be appreciated.

 

[dopefisher]

you need a new video card, bottom line.

 

[boondog]

The original video card that was in the system was Xtasy 9600 256mb. We put in the older card to troubleshoot if it was the video card causing the problem.
We also uninstalled the old driver before switching the cards. We also tried a ATI7500 video card.

None of these fixed the problem