The following should help if you get "2 black bars" . If only one , it would likely be the display resolution
Enable NVidia Display Adapter Scaling
1 Right-click on your desktop wallpaper, then select "NVidia Control Panel."
2 Double-click "Adjust desktop size and position" under the "Display" category in the left pane.
3 Select "Use NVIDIA scaling" and then press the "Apply" button.
Enable ATI Display Adapter Scaling
1 Right-click on your desktop wallpaper, then select "Catalyst Control Center."
2 Double-click "Display Panel Properties," and then "Image Scaling" in the left pane.
3 Click in the check box next to "Enable GPU scaling" and then select "Scale image to full panel size."
4 Press "Apply," and then "OK" to save the changes.