The following article will explain the steps involved in changing your screen resolution on your PC.
Locate your Control Panel on your PC
Select 'Adjust Resolution'
Here you will be presented with all the available options for correct monitor display - please identify how many monitors you have/ require and adjust the display/ orientation and resolution methods listed.
Please note, there will be a listed 'recommended' resolution type for your screens stated in the above - please select this option first before attempting other methods.