I recently purchased both, Arma 2 and Arma 2:Operation Arrowhead on Steam. I ran both of them and BOTH crashed, for ARMA 2 it crashed on the little boxes with the ticks in. On Arma 2:OA it crashed on the loading screen, the "please wait" screen. When ARMA 2 is launched it just displays a normal windows box saying "ARMA 2 has stopped working" For ARMA 2:Operation Arrowhead a box comes up saying "Bad Serial key Given on Setup" I'm confused because I don't know why this is happening and I hope one of you can help me :)?