Hi, I have found a solution, its working for me. Go to game directory (e.g. c:\Program Files (x86)\Steam\SteamApps\common\DayZ\), right click on dayz.exe and properties, go to compatibility tab, check the "run this program in compatibility mode for:" and choose windows vista. I'm running on GTX 660 and windows 7 and i downloaded beta version of nvidia drivers.