Disclaimer: I've never done this in Windows 2000, only NT 4 and 98, 95.
What you want is to bring the computer up in "Safe Mode". I think you can do this in 2000 the same way as 98. Press the F8 key while windows is starting up. This should bring up a menu on which you can select "Safe Mode". From here windows should boot without the normal drivers.
Once up in Safe Mode you can backup your data, or try to diagnose the problem by uninstalling suspect drivers. (You can also tell drivers not to startup with windows through Start->Programs->Administrative Tools->Services, though this is a bit tricky if you can't identify which service relates to the driver you're intent on disabling). If you examine the BSOD it might tell you which module is causing the crash (I don’t remember, as I haven’t seen one in quite a while).
After uninstalling suspect drivers you should try to restart the PC as you do normally and see if you still get the BSOD.
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-Jeff
Rome did not create a great empire by having meetings; they did it by killing all those who opposed them.