I have just done a clean install of WinXP Pro. I logged into Steam, downloaded the game files and I also installed BF1942 and BF2. So here's what happens:
Half-Life 2/CStrike Source/BF2: Game runs for 5 minutes or so then computer restarts. No "Windows has recovered from a serious error" or any error message or any sort.
BF1942: Runs fine.
My specs are in my signature (which is outdated since I run the 3000 at 1.8GHz now with C'n'Q on. The Nvidia driver is at 71.89 currently, and I've installed the nForce 4 chipset drivers and the AMD drivers as well. I'm suspicious about the videocard. Also, it seems like HL2/CSS/BF2 all use DirectX 9, and BF1942 uses DirectX 8. I've done a reinstall of directx/WinXP, but the problem continues.
Anyone have any ideas?