Are the crashes random, after a certain period of time, or associated with particular events in the game?
Are you shutting down all non-essential programs (especially anti-virus) before starting the game?
Have you checked for updated video drivers, and installed the latest critical updates for Windows?
I played the game fine with a Windows 98SE, Duron 900 (later 1300), GeForce 2MX, 512MB system. The only obvious potential problem as far as system requirements is your RAM; Windows XP take a good chunk of that for itself.
Troubleshooting Tips (& manual install procedure)