What is the STOP code? The number next to the word "STOP" will often tell you what the error is. Here is an example of a BSOD:
The stop code is 0x0000001E in this example. What is yours? When you find this out, you can go to http://search.support.microsoft.com/kb/c.asp , select "Windows 2000" from the drop-down list in step one, type in your STOP code in step 3, and click "Go". This should give you some basic info to start troubleshooting the error.