OpenGL freezes on every game i play

I have been having a problem with many of the games on the market these days like Quake 3, Tribes 2, and flight simulators(all of them play in OpenGL). I Have windows 2000 could that be a problem?. What has been happening is that it will play for a few sec then just lock the whole computer up. I have tried everything i even have a Hercules Dual Dusplay video card and a pentium 2 proseccor. if you know the answer could you please e-mail me back? It would be a great help.

                        Keaton D