Right click anywhere on the desktop and choose 'Properties'.
Choose the 'Settings' tab
If you have a widescreen laptop or monitor (width roughly half as long as the height), set your screen resolution to 1280 by 800 pixels.
If you have a full screen laptop or monitor (width about the same as height), set your screen resolution to 1280 by 1024 pixels.
Click 'Ok' to exit out of the display properties
Your screen should now display properly.