Come on, it`s pretty unlikely that anyone who has genuinely bought the game is going to give you their CD key ? Since it is impossible to check whether you are a valid owner or not, then I am closing this thread.
If you are a genuine owner, then you will still have your original install discs, and I am sure you can contact Microsoft and obtain a key if you talk nicely to them. They are quite easily found - www.microsoft.com ;)
DanB
DVD ReviewerJoin the fight against cancer.
(Costs nothing and takes little effort ;-))