Recently, my computer started to set my 4k monitor resolution to 1024 x 768. Not kidding! My solution was to disable and enable the Display Adapter.
How to fix your Display Resolution in 4 easy steps:
1. Open Device Manager by going the Start Menu and searching for ‘Device Manager‘.
2. Find the display adapter and right-click to select, ‘Disable device‘.
3. Select ‘Yes‘ when prompted.
4. Right-click and select ‘Enable Device‘.