Another option is to uninstall both games and run some registry cleaning software like RegCleaner, since its likely a registry problem.

Did that too and no change.

Well, I got the new KB AP Crossworlds GOTY Edition on DVD. After I the install and the Error screen for the Key Code, I put in the new DVD's Key Code and the game started up just fine.

New rule: NEVER Deactivate a game on a computer when you intend to reactivate on the same computer!

Thanks for your help though Sneaksie.