If a black border appears around the screen when using an AMD graphics adapter, this may be due to a change in their drivers which causes it to incorrectly detect a full-HD monitor as a TV and automatically apply a 10% underscan
Firstly, update the graphics driver. If that doesn't fix the issue, change the overscan setting manually:
- Start Catalyst Control Center
- Navigate to My Digital Flat-Panels | Scaling Options
- Tick the box for 'Use the scaling values instead of the customized settings...'
- Set the overscan slider to 0% (the far-right setting)
- Click Apply
If two monitors are in use, change to the second one in the drop-down and follow steps 2-5