Although if I start Arma 3 from within Steam i can choose to start in windowed mode. My monitor will accept it and it works. However the game does not show and accurately where my mouse pointer is actually at(shown in provided picture). In order to fix it have to go into video options and change display options from windowed to full screen and everything works just fine(which is what should have happened from the start). My desktop resolution is 1920 X 1200.