Hey guys, need some help.

Is there a way I can change the Product Key of
Windows 2000 Server without reinstalling it?

We have a Server with Windows 2000 Server installed in it but
the installer used is a pirated copy. We purchased a licensed
Windows 2000 Server with 5 CALS OEM pack to make it licensed.
It is the only domain controller in our company and I am not
sure if i can restore its original active directory if reinstalled.

can you give me a software or even a manual way of changing it?