So, I have AII , OA, PMC, and BAF. They were all purchased on steam. I am unsure of the exact relationship between the two, but when I started up AO after installing everything, there were two Armas in the addon listing and only AO would launch combined ops at all. My PC is a 64 bit Win 7 and I'm thinking this may have lead to my computer putting steam and the Arma files in a X86 prgram files folder. meanwhile another folder resides in the regular program files but that only appears to contain battleeye. I have deleted all of this and am starting a fresh install because I was constantly getting a error in Steam that stated one file was missing and would be reacquired. This seems like a lot of trouble if I were just wanting to play combined operations from OA, but I have been attempting to get I44 to work as well, and when I follow that mods instructions and install in the arma II folder in steam, I think the mod does not detect the files in the arma ii folder because I have have two armas showing up in addon selector, and I can only launch combined ops from AO. I dont know if this is relevant or not, but I cannot seem to activate or deactivate any of the addons from that addon menu, in fact, the buttons are kind of greyed out.