I have an idea, try going to your (C:) files and go to Program Files (x86). Go to the steam file and go to the steamapps file. Go to Common, then dayz, and then right click the dayz launcher (you might have to left click one time to select it) and go to properties. Go to the compatibility tab and uncheck the box that says "Run this program in compatibility mode for:" It might work and might not, but it's worth a try.