Maluson

For non steam users: Basically the only solution (the simplest but the longest;) ) is to uninstall your whole game (make a backup of all your settings if you really want to) and reinstall it properly. Properly means : - Install Arma 2 first, - Install Arma 2 OA IN THE ARMA 2 FOLDER, the game should ask you where you want to install it but by default it should automatically point to the Arma 2 folder. If it doesn't then make it do. - Install Arma 2 BAF and PMC if necessary, - Install last patch (i.e. 1.57) With the first two steps, the game will automatically be Combined Ops. Last advise, before installing OA (after installing Arma 2 then), check if the ArmA 2 registry contains the correct MAIN value. For more details on this and in order to avoid that the game doesn't recognize Arma 2 go to : http://forums.bistudio.com/showthread.php?t=112568 as posted by AlienXXI Hope it helps. Regards.