I have a feeling you are using ATI graphics card
If you are using ATI graphics card, you need to follow the steps
below to set the scaling option
Try setting to 16:9, and 1920x1080 resolution first
After that:
1. RIght click desktop and select catalyst control center
2. On the top left hand corner click graphics, and select
desktops and display from the drop down list
3. Look at the bottom, you will see the monitor u have connected
to, it will have a 'number 1' on the monitor
4. Right click the monitor and select configure
5. On the tabs on top, there should be a tab called scaling.(im
not sure because ive send my monitor for repair and this monitor im
using now is of a smaller resolution, so i do not have that
option)
6. The scaling option should have a slider for you to drag, play
around with it until u get the whole monitor covered