It seems like a basic fix, but it can often correct screen glitches, such as horizontal lines.
Change your monitors refresh rate.
Switching to anotherrefresh rate settingcan help with lines and screen flickering.

This can fix a variety of tech issues and could get rid of any flickering lines on your screen.
Try a different monitor.
Doing so can help you determine if the lines are because of your computers screen or the computer itself.
Check your monitor while its disconnected.
If you see any distortion, it means your monitor is damaged.
Detach and reattach the keyboard.
Close and reopen your laptop slowly.
Examine when the lines appear on the screen as you open it.
If the lines only occur at a certain angle, the cause is likely damaged wiring.
Use your laptop on a hard surface.
Disable Instant Replay if it’s enabled.
The option is in the app’sRecordingsettings.
This is only relevant forAMD Radeon ReLiveusers who have this feature turned on.
plant the latest operating system updates.
Old software conflicting with newer hardware could cause the lines on your system screen.
It’s easy toupdate Windowsorupdate macOS.
Check the monitor connection.
If you notice the image improves or worsens while touching the connecting cable, it may need replacement.
Remove magnets and electronics.
Clean your system and monitor.
Dust may be causing them to overheat and create visual distortions.
Change the screen resolution.
It’s easy toedit the Windows screen resolutionor the parameters on your Mac.
So, give this a go before moving on to the more complex steps below.
revamp your Windows equipment drivers.
Check for driver updates for profiles associated with your monitor and screen.
Some users have found thatdowngradingtheir video card driver was the fix.
If you recently upgraded your drivers, considerrolling back to the previous versioninstead.
Search your rig for a video troubleshooter or program compatibility tool.
If you get presented with recommendations for other troubleshooters, run those too.
your setup will attempt to fix any problems automatically.
Reset your monitor to its factory options.
If youre using an external screen, use its built-in controls, not your computers.
you could access these tweaks via a physical tweaks or Menu button on the monitor.
Upgrade to a new monitor, orbuy a new laptop.
To troubleshoot the issue, turn your box off and on again.
Also, unplug the monitor-to-PC cable and plug it back in, making sure the connection is secure.
Try another monitor to see if the problem is with your PC.
Also, try resetting your video card; if nothing else works, replace yourvideo card.
If you’re using a CRT screen, trydegaussing the monitor.
Also, try setting your screensaver to an all-white image and letting it run for a few hours.
you could also try using the JScreenFix tool, which fixes stuck pixels.