The steps below work for both laptop monitors and external monitors. Now, follow the steps below to check your PC’s display settings: If you know how to replace the LCD yourself, or have a friend who can do it etc, you could try buying a cheap one on eBay or such. If there are vertical or horizontal lines on the screen it could mean that the refresh rate on your display needs to be changed.This will improve contact and green lines Monitors aren't cheap and if the lines are affecting a laptop screen, you might be looking into an even greater expense. The lines on the monitor are moving or jittery. My computer has been freezing/crashing at random times.