I bought 2 copies of WoW when it launched, and gave one to a friend. He has since lost his CD key, and needs it to recover his account or some such. Unfortunately I didn't make a note of whose key was whose.
Is there any way I can determine which of the CD keys was used to activate my account? That way I can give him the other one.
Best Answer
Once a key is used, it is permanently associated with an account, but you won't be able to look it up anywhere:
(Source: Authentication Key FAQ.)
However, if he uses the wrong key, it'll simply tell him that the key has already been claimed. There are no negative consequences to using a wrong key, so give him both and one of them should work fine.
Edit: As @wikwocket pointed out, a potential downside is that your friend could become privy to your own key. If that's a concern, one way to guard against that could be to try a recovery process on your own account and input an account key -- if it goes through, it's yours and your friend has the other one. Or the other way around.