windows 2000 prof.

You ust have replaced it with a motherboard which was not identical to the old one...

1. Try to boot into safe mode, unistall all drivers (USB, VIDEO, system files) from the device manager. Reboot and it may work.

2. More than likely #1 will not work, but it is worth a shot. Hopefully you have a spare drive to where you can reload 2k, slave the existing drive and copy your data files back over.

3. Some suggest doing a re-install of 2k on top of th old one / repair old data with 2k cd... When changing motherboards, this does not work and causes more down time than a remedy.

Good luck

Win2k shouldnt matter if the motherboard is not identical, But it is best to use an identical MB. The problem is that the system is blue screening upon bootup, and it is set to auto reboot upon an error. You can do as above and reinstall over itself, this should fix the problem. If it does not, you may just have a bad motherboard (even though its new).
You should first try booting to safe mode with minimum drivers. If this fails reinstall over itself, if this fails take the motherboard back.

you have to run the utility drivers for the motherboard if that doesnt work, try to reset the bios on the motherboard by moving the jumpers from one side to the other for 10 seconds and then reseating them look at the motherboard diagram to find the jumpers for the bios settings ,reset data configuration on the system bios advance set up .and then windows 2000 should load and boot up normally ..........

Please refer to Microsoft Knowledge Base Article 824125

HOW TO: Replace the Motherboard on a Computer That Is Running Windows 2000 or Windows Server 2003

The article describes the steps that you must perform to reconfigure Windows to work with the new motherboard (upgrading an existing motherboard or replacing a failed motherboard).

http://tinyurl.com/j9u7