when you turn it on the screen start glitching

Rebooting is cliche for a reason

Reboot your computer, your printer, your router, your mobile phone, your USB hub and everything else you’re having a problem with. By reboot, I mean turn it off, wait a good minute or two, and turn it back on.

Reinstall and update your applications

Rebooting clears out the temporary gunk hanging around in your computer’s memory but it won’t affect anything permanently written to disk: Corrupt setting files, damaged data that should’ve been trashed but hasn’t, and other bits of digital detritus will still be hanging around.

An app reinstall can help fix that, and you should give it a try if one program in particular is proving problematic. Uninstalling and reinstalling an application not only clears out any corrupt data or broken settings, it also ensures you’re running the latest version of the software, complete with the latest compatibility updates and bug fixes (assuming you get it from the web).

Check for spyware and malware

If you’re still having problems with system crashes and general sluggishness, a spyware or malware program may have taken root on your machine. Update your antivirus and antispyware software to the latest versions and run the most comprehensive scans they has. Lifehacker has a good round-up of the best choices.

Do some simple investigating

Some simple detective work can do wonders for finding solutions to PC problems. It’s not always possible, but if you’re having trouble with one bit of hardware, try replacing it with another: If it works, you’ve identified the source of the issue and can take appropriate action (like buying a new keyboard).

Reinstall your operating system

We’ve talked about emptying your computer’s memory and cleaning up data files, and reinstalling Windows or Mac OS is the ultimate version of that. In the past, this used to be a long-winded and potentially dangerous process, but Apple and Microsoft have now made it so straightforward that it’s almost worth doing regularly whether you’re having problems or not.