Assuming you are on Windows: Try changing the display settings in Control Panel or Options-System-Display. Try setting for the lowest screen resolution like 800x600 and see if it fits the screen better, it will revert back to the previous settings if you don't do anything after a few seconds. That should give you an idea if you can make the display screen look more normal. If changing the display settings do not change the appearance then see how it looks on an external monitor, if the external monitor shows the same problem then the problem is a defective graphics adapter on the system board.