I have a Z27n display on a Z840 workstation running Windows 7 (64-bit). The optimal screen resolution is 2560x1440 but keeps getting changed to 1920x1080 without my input, usually after waking up from sleep. The Windows control panel only gives me the option to go up to 1920x1200. I just installed a Nvidia M4000 graphics card, I'm wondering if it could be some sort of conflict with the driver or some other software. I would like to go back tot he 2560x1440 resolution.