Hey i have got windows XP Home edition With a Gforce 2 mx 400, 1800 amd athlon , 512 ddr ram sb audigy. I had the graphics card in my old comp with windows 2000 and it worked fine. Now when ever i play ANY open gl games like Counter-strike for example. I can run it in software graphics, but when i turn it on open gl even 600 x 400 it gets in then like 2 - 3 seconds later it freezez for about 15 seconds then works for 3 - 6 seconds then freezes again, it keeps doin this to any games that uses open gl or 3d graphics, I dont get it … Please help me, Oh and btw i have reinstalled the video card several times, played around with the settings, put old drivers new drivers u name it, and even reinstalled the sound card. PLEASE help Thanks in advance 
Sounds like you either have a system conflict or a heat problem.
To see if it’s a heat problem, remove the case shell and set a fan blowing right into your case.
Fire up a graphics program and see if you still get the stutter. If no, then you need to consider some cooling options.
If yes, then you’ve got bigger problems. Here are a few things to try:
Remove and reseat the video card, inspecting it for any damage.
If the PCI slot just above or below your graphics card is taken, remove said card(s) and locate them so as to leave an empty PCI slot between your graphics card and other cards.
Check your hardware settings for conflicts.
And finally, consider a hardware failure either in your video card or motherboard.