Lost CD Key from Arma 2: Combined Operations

[ThatOneGuy]

I've lost the CD key for Arma 2 Operation Arrowhead from my Combined Operations package. I still have the Arma II one but not for OA and I was wondering if there was anything that I can do to recover it. It is a retail copy of the game and for some reason i cannot find the CD key for just the one game. Can anyone tell me what I can do to get it back?

[Nicholas]

You must contact the place where you purchased the game. Bohemia Interactive is unable to do anything in a case such as this.

[Kindling]

If the game is installed on your system, you can recover your CD Key through the registry.

Click the start button then type 'regedit' and press enter. Navigate through the tree to HKEY_LOCAL_MACHINE\SOFTWARE\Bohemia Interactive Studio, right click on the 'Bohemia Interactive Studio' folder and click 'Export'. Note that the new file contains the CD Keys for all your BiS games and should be stored securely.

If not, you'll likely have to repurchase the game - unless you're using a platform such as Steam, for which you should refer to this Steam support article.