th3flyboy 0 Posted June 30, 2010 Hi, I decided to pick up A2 CO off of steam (I have a 505 version of A2, but I figured I'd install the steam one because I wasn't sure if it would mesh with OA from steam) and it gives me the message: "Bad Serial number given in setup". I had uninstalled the A2 from my 505 copy before installing A2 Steam, but I'm wondering what could be causing this and how to fix it, as it is blocking playing A2. Share this post Link to post Share on other sites
Bulldogs 10 Posted June 30, 2010 Search the steam forums for "invalid CDKEY" or "Bad serial" and there is a solution there posted by Dwarden. Run regedit and search for a key "Arma 2", it'll be under a key of Bohemia Interactive, delete the Arma 2 key there, then try the Steam fixes again. Share this post Link to post Share on other sites