I have a GeForce 2 Pro 32mb, and i have the latest Nvidia drivers and i can't play for more than 45 min's (tops) without a hard lockup. It's happened with 5 min's before too.
I have the same card, and had the same problems under XP. Here's what fixed me up:
Use the 23.11 reference drivers.
Goto Display Prop.-Settings-Advanced-Troubleshoot, then disable Enable Write Combining.
Goto to Admin. Tools-Services, find NVIDIA Driver Helper Service, stop it, then disable it under properties.
Hope this helps.