Integrated graphics will prob not run it, I run it reasonably with a 5 yr old Geforce 8800 GTS. Arma 2 is 3 years old.
How many frames per second do you get, and on what resolution/settings? Arma II may be old, but at max or near max settings in 1080p, it's still pretty demanding. DayZ (mod) even more so because of the wasted resources.
That's another thing: OP, what's the resolution of your monitor?