I have just recently bought Operation Arrowhead and saw that you can combine it into Combined Operations. The articles that I read state that OA look for Steam or Normal ArmA2 however I don't know if it will find the GreenManGaming's copy of the game which is found in Program Files/CapsuleGames.
Does anyone know if this will be an issue? Operation Arrowhead is still downloading so I can't test it for myself.
Thanks in advance,