Do you have any programs running that might affect it? Like an Overlay program. Teamviewer... samsung magician
Update nVidia drivers to latest stable or beta (tick "clean install")
Did you try removing/renaming the profile/settings folder from above?
No funny DPI options set? just 100% default?
Maybe try changing resolution (in game, not windows) to 1366x768 and see if full screen works... is so try 1080 again.
Clean Boot:
