White Bar on My Computer Screen

A white bar appearing on your computer screen can have several causes, ranging from a simple incorrect setting to hardware failure. By testing various components in your computer separately, you can determine the root of the problem before deciding whether to repair or replace the machine or monitor.

An incorrect resolution setting for your monitor can cause bars on one or more of the outer edges of your screen. Check the screen resolution setting in the Windows control panel. Set the resolution to the recommended option and see if it fixes the problem.

Problems with video drivers can cause graphical glitches, including lines on the screen. If you've recently updated your driver, revert to an older version that you know worked. If that doesn't work, install the newest version available from the manufacturer of your video card, laptop or, when using integrated graphics, your processor.

Broken video hardware often produces screen glitches, including bars. If you're on a desktop with a video card, put a different card in the computer to test for this possibility. If your computer uses integrated graphics, you can temporarily move a video card from another computer and see if that fixes the problem. On laptops, video hardware is generally not user-serviceable.

If the computer hardware isn't at fault, the monitor may be. Switch to a different screen to see if the bar goes away. For a laptop, plug in an external monitor, and if the white line only appears on the laptop's display, have the screen replaced.