I know some games work sporadically, if at all with win2000, has this games been working for a while or did you just install it?
Sometimes newer games require an update on the drivers for various devices on your computer such as the graphics adapter, sound controller, etc. Do an update of your drivers, and make sure DirectX is updated as well. Also, check the documentaion that came with your game, you may find that it is'nt designed to run on Win2000. Lastly, most popular games have forums on the web that offer specific support for your game, I am certain you're not the only one having this issue.
If you'll tell me what game you're playing, I will see if I can find a support site for it. Good luck.
I\'m already visualizing the duct tape over your mouth...