I really dont recomend windowed mod in day z due to the high attention you have to spend from getting yourself killed, but. You can enable windowed mode in settings. to get to this: 1) Start six lanuncher 2) dont select a server (just hit play) 3) Arma 2 will be up (go to settings) 4) windowed mode will be an option 5) select the server you want from the Multiplayer Tab I recommend Advanced system care (free program) to help speed up/ clean your computer of unnecessarily files/ data. it also has a "Boost" feature which shuts down tasks that are not needed while you play the game, this of course needs to be setup. also i recomnd running a defrag on your hard drive, that may increase your frames.