Way to change cd keys? (please don't delete, good reason)

[flxnimprtmscl]

I bought a few games recently of one of the forum members on accident he forgot to include the keys with them. Me being impatient I just dl'd a keygen for them so I could play while I waited for the keys to show up in the mail. Well now I've got them and I'd like to be able to at least try playing online on my 56k not to mention registering them. So, any way to do this without re-installing them? Oh, the games in question are BF1942 and MOHAA btw. Thanks guys.

 

[flxnimprtmscl]

Uh, actually nevermind. I just remembered I've got a new board coming in a day or two and I'll be doing a fresh install of everything anyway. Oh well.