In both my win10 and win7 machines, my native is set to 1600x900 game is set to 1366x768 fullscreen. Both are running on 22 inch wide screen Acer monitors. I have no borders and have no problem with taskbar. The win10 is running a Nvidia gtx1060 and the win7 is running a Nvidia gtx570, no changes made anywhere else. It has always worked fine, so I leave it alone.