After you manaully uninstall a TS3 pack it is recommended to use a registry cleaner like ccleaner. You probably did not remove the registry entries and the system thinks the game is still installed. The EULA you agree to when you first started the game. The EULA states EA ACCOUNT AND GAME REGISTRATION WITH THE PROVIDED SERIAL CODE. REGISTRATION IS LIMITED TO ONE EA ACCOUNT PER SERIAL CODE AND IS NON-TRANSFERABLE. Translated - once you register the game to an account only that account has the license to play it.
I ran CCleaner after I tried to manually install the game. I couldn't manually uninstall the game, because I had already clicked uninstall when the CD asked me, and the Supernatural files weren't there. But when I put the CD in, it asks me to uninstall, though I can't find any trace of the Supernatural files.
