....don't know why my original reply hasn't shown up, but to recap - if you
didn't buy it and get a copy of the license, you weren't using a legal copy.
You'll need to buy it (or might's well go get XP at this point).
Yes, or KeyFinder from www.magicaljellybean.com - does the same thing.
Note however that a) this requires that the existing installation is still
bootable, and b) sounds like the OP was not using a legal licensed copy of
Windows to begin with.