Yeah, check drivers, stuff in the background and play with the game settings a bit.

I have 600mhz Pentium 3, GeForceFX5200 128MB, Soundblaster 16, and 512RAM and I can run the game with x4 AA and x8 AS totally flawlessly, with all the settings on atleast Medium.

If you havent, try turning off shadows/reflections (unless you really want them).