If your computer technician speaks to you only in tech jargon while attempting to repair your PC, beware.
8. Turn it off, then turn it on again
If you experience a problem with your computer, try turning it off and then turn it back on again. Do this even if you are unable to shut down your computer properly - turn off the mains if you must.
It's the best thing you can do to save yourself a good bit of money: simply switch it off, wait a few minutes and turn it on as per normal again.
More often than not, rebooting your computer will solve the problem.
This trick applies to other devices, such as your printer or scanner as well.
Only call me when your computer fails to boot up properly, or is still experiencing problems despite multiple attempts at rebooting the system.