OK guys, here's the deal. I own an AMD Athlon 1.4 ghz with a Soyo K7-ADA motherboard and 512 MB of DDR ram and a geforce 2 MX/MX 400 64mb

When I had 256mb of ram, and I played Half-Life TFC or DoD, it would freeze up on me alot. When I bought Tony Hawk 3 for the PC, and I served a game, it would freeze up within the first 20 minutes and if I joined an online game, I might be able to get 30-60 mins of playing time and it would freeze. In single player Tony Hawk 3, I would play for maybe 2-3 hours then it would freeze.
When I upgraded to 512mb, Tony Hawk runs PERFECTLY. I made my own server and played for about 2 hours with no problems, but today I got Global Operations and installed it and started a game and within maybe 30-60 seconds, it froze up on me.

On my old PC, 733mhz P3, 448 PC133 SDRAM, Soyo SY-6VBA, and Voodoo 3 3000 16mb, Half-Life TFC and DoD ran fine with no problems and I could play for 5 hours with no problems. Same goes for Tony Hawk 3 and Global Ops.

I also noticed that in CS with my old computer I would get 100 frames per second on average, but now with the new computer, same settings, it would be maybe 40-50 frames per second average so I'm thinking it is either my Geforce or my motherboard.

I was just hoping someone here would know the problem so I could solve it. Any help with this would be great.