Call of Duty delux - CD key problem. I have the Deluxe edition of Call of Duty (COD) and entered the wrong key when I installed the game. I can play the single player version but when I try multilayer I get the message "CD key is in use, please try again later". On the box there are two key numbers one for COD and one for united offensive (UO Add file Call of Duty: United Offensive Demo. Location Files. Filename coduo_sp_demo.exe Category Demo. Uploader GameWatcher. Added Sep 25th, 2004. Size aWbbMz.