The serial number found in registry is not a correct Arma2 :OA key. Please reinstall Arma 2 OA and restart PMC setup. I keep getting this after reinstalling OA about 3 times, trying without Anti Virus , running as admin but still nothing. This is with Direct Download of game from Amazon (Meridian4). Really irritating as I want to do the stories, get higher res models for domination etc. Any help would be appreciated!