ViaDmomus

Hello i have a big problem : When i start the Arma 2 OA everything works perfect but when i try to start a new campaign or scenario the game crashes and it gives me the legendary error : It has stopped working" i dont know what is the problem i was able to play arma 2 on very high settings my rig is : Intel Core 2 Duo e7200 2.53 Ghz 2 GB RAM DDR 2 667 Mhz ATI HD 5670 1 Gb GDDR5 stock clock 250 GB HDD