ok i fixed it idk if this will help but if you have the combined operations disc what i did was click the start key and click on computer. then you see the operation arrowhead icon (your operation arrowhead install disc must be in) and after you install it you click play and a menu thing will pop up with the option to choose serial key saved by internet or by disc which means your disc will have to be in everytime you play. choose by internet and then you will get a box where you type in your serial key that was on the back of your operation arrowhead manual and type that in(you have to put capitals and dashes so it will look like this 2DYL-61T0-8C09 exc) and then you should be set. but run arma 2 original first the press alt tap and open operation arrowhead and then exit both and you should be done. let me know if i helped.