My game is telling me that my serial is incorrect. I have the Steam version of ArmA 2 and a retail copy of OA. My physical media has gone missing, so I only have the key. I've managed to acquire the game files and have gotten it installed and patched, but I need to find a way to input my serial number. I've found the key entry in the registry, but have no idea how to change it to the proper hex code. Any assistance here or am I out of luck?