So, I've tried every solution I could find in these forums and the interwebs, but nothing works for me! Until now this is my 10. try to run both games simultaneously. Both Arma 2 and OA are retail-versions, non-steam. I'm really disappointed that I have to spend like 8-9 hours for this, when this has been an issue for a long time - I just want to play :(:( Many of my mates don't have OA and we play Arma 2 vanilla alot, theres no chance in just installing OA and be ok with it, I WANT both, because I paid for both.
Please let there be a magician out here :(