Change CD key in Steam

[pepe.lp 0]

Hi Guys

Long story Short i was setting up my sons Steam account for ARMA II and placed my CD Key in now i dont know how to change it .. how do i change the CD key please

[Drogur (DayZ) 169]

http://forums.steampowered.com/forums/showthread.php?t=2850936

[cindyanne1 41]

Hmm wonder if I could change a cd key manually. My husband I would really like to play together but we'd need two copies of Arma. I don't mind buying another copy, but the game is already installed on both our computers under the same cd key. But I didn't use Steam to buy it. :\