40 ways to fix your PC before you call an expert (16)

16. Test on another computer

Use another computer to test your malfunctioning mouse/camera/printer, or just another USB port, to help you work out where the fault lies. If the problem vanishes, it's not the device itself that's to blame.

40 ways to fix your PC before you call an expert (15)

15. Re-install Windows

This is the scorched earth policy -- but it's not as drastic as you might think. Many PCs and laptops come with recovery discs or a recovery partition on the hard drive that you can use to return your computer to the state it was in when it arrived from the factory. Of course, it goes without saying that you'll need to install your software again and you'll lose all your personal data, so you'll need copies of your important files (photos, university essays etc). 

40 ways to fix your PC before you call an expert (14)

14. Registry cleaning

The labyrinthine settings file that is the Windows registry can cause errors, program crashes and system restarts if something has gone wrong deep within it. There are plenty of third-party tools that will scan it for problems for you, though not all of them are trustworthy -- Glary Registry Repair is one of the ones you can depend on (though as with any advanced tweaking tool, use at your own risk -- you do back up, right?).