Why Is There a Line on My Computer Screen? (And How to Fix It)

Which one do you have?

Line shows on an external monitor too

Points to the graphics driver or graphics hardware, not the screen. See fixes

Line only on this screen

Points to the screen panel or the cable connecting it. See fixes

Fixes to try (easiest first)

1. Restart the graphics driver

   On Windows press Windows + Ctrl + Shift + B. The screen blinks once. Check whether the line has gone. [2]

2. Test with another screen

   Connect an external monitor and press Windows + P, then Duplicate. If the external monitor looks fine, the laptop screen may have a hardware problem. [1]

3. Laptops: run the built-in screen test

   On Dell laptops: turn off, hold D, press power, and watch the solid colors. If the line appears during the test, the LCD may be faulty. [1]

4. Monitors: run the monitor's self-test

   Unplug the video cables and run the monitor's self-test. If the line still appears, the monitor panel has a hardware fault. [2]

5. Update the graphics driver and BIOS

   Corrupted graphics drivers can cause lines. Update the driver and BIOS, then restart. [1]

6. Roll back the driver if lines started after an update

   Device Manager > Display adapters > your adapter > Properties > Driver > Roll Back Driver. If it's grayed out, there's no older driver to go back to. [2]

7. Reseat or swap the monitor cable

   For separate monitors, make sure the cable is firmly in at both ends with no bent pins, then try a known-good cable. [3]

Is it worth fixing?

If the line shows on other screens, the fix is usually software and free. If it only appears on the screen itself, even during the built-in test, the panel or its cable needs repair or replacement, so check your warranty first.

Repair or replace? Try the calculator · Not sure this is your problem? Take the quiz