Windows 10 Horizontal lines on screen

It could also be a faulty monitor. Have you tried connected a different working monitor to your computer or borrow one from a friend to try it? This will often fix this problem.

If the problem persists after trying another known working monitor, it could also be a faulty GPU card or GPU chip on the Motherboard and that takes more troubleshooting such as kemical suggests. Many motherboards have an embedded GPU chip built in on the Motherboard, so to test your GPU card, simply power off and remove the card from the inside of your computer case. Power back up, access the Motheboard BIOS and set your Graphics Card to DISABLED, save settings and reboot. There are different BIOSes that do this differently; you'll need to consult your computer Owner's Manual online for your particular computer or Motherboard. Some BIOSes will have you ENABLE your onboard GPU chip they call it Onboard Video or similar. The BIOS then will switch your computers display to run from the embedded video chip on your Motherboard. This is important even after you physically remove the GPU card if you have one, as not all BIOSes will do an "auto-switch" and auto-detect you've removed your GPU card and switch back over to the built-in graphics chip. If your video problem abates, you simply have a faulty monitor and it must be replaced. New flat screen 19" LCD monitors run about $100 online with free shipping. I had a customer with a nearly identical problem last year. He bought the new LCD monitor, and he's been good ever since!

Good luck,
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