Alright, I've had Arma 2 for a little while now. My household shares a PC for gaming, and the Arma II profiles helped with this just fine. But until recently, I've been playing DayZ and my brother wants to play. Right now characters are linked to your GUID/CD key so we can't really share our copy of Arma 2 (we'd have to share our character's progress, neither of us wants that). He recently bought CO from amazon and we were hoping to be able to play on the same machine and in some way have a method for launching CO with our own CD keys so when we connect to a DayZ server, our own character is loaded.
The current installation of ArmA II: CO is from steam.
One method I though of, but want to know if it'll work before I try is using regedit (which I learned how to do after I lost a CD key for one of my games). I checked the registry and there seems to be a KEY register at:
HKEY_LOCAL_MACHINE/SOFTWARE/Wow6432Node/Bohemia Interactive Studio/ArmA 2 OA
It looks like the key is stored as hexadecimal. I want to know if changing this to use the key he got from Amazon would work. I'm not sure how to convert it to hexadecimal exactly, but we figured we could install it on another computer and get the key from that one (the other computer can't run Arma 2, otherwise we would use it). I just don't want to screw anything up.
Alternatively, we could get another copy of windows and install it on another hard drive/partition, but that's more trouble than it's worth and not really necessary.