I'll ask the obvious question, do you have a legitimate copy of this game. And where did you obtain it? If it wasn't from a store it is possible that it's a non-legit copy.
Buy the game. If you did, then the CD key should be either on the manual or the CD case.
Otherwise, don't ask for help with software that have not been legitimately purchased and asking for keys (even if you bought the game and lost the key) is not allowed on these forums.