Hey CF, so I am going to bid on some used PC games on eBay and I need your help. Now these are relatively new games so these need CD Keys to run and play mulitplayer. If the previous owner already registered the CD Key and then uninstalled the game can I still use the game, or has the CD Key been registered permanently and I will never be able to use the game? I just wanted to know so I dont waste my money. Thanks everyone.