Your description is short in pertinent info regarding the booting problem. Here?s the MSKB article that deals with OS problems.

Q315396 ? ?How To Troubleshoot Startup Problems in Windows 2000?.

However, you might also have a hardware problem: bad Power Supply Unit, bad memory module, motherboard failure, etc. Try to start the PC with minimum hardware devices. In other words, remove all external devices.


P.S. For windows 2000 you should post this in the corresponding Forum.
Good Luck,

Cetin


Trying to unweave, unwind, unravel
And piece together the past and the future,


T. S. Eliot