Originally published at: http://www.howtogeek.com/173760/htg-explains-why-does-rebooting-a-computer-fix-so-many-problems/
Ask a geek how to fix a problem you’ve having with your Windows computer and they’ll likely ask “Have you tried rebooting it?” This seems like a flippant response, but rebooting a computer can actually solve many problems.
However, reinstalling Windows (performing a “Refresh or Reset your PC” operation in Windows 8 terms) will wipe away everything on the computer’s hard drive, restoring it to its formerly clean state.
This is simpler than looking through the computer’s hard drive, trying to identify the exact reason for the problems or trying to ensure you’ve obliterated every last trace of malware. It’s much faster to simply start over from a known-good, clean state instead of trying to locate every possible problem and fix it.
Your average geek will know this already, but in case a novice comes along and reads this article you might also want to mention that they'll need to back up their personal data.
When you have a laptop, try removing the battery and AC cable between reboots. This prevents current from going anywhere in your laptop, so RAM gets properly emptied and stuff.
Similar to the 10-10-10 reset for the routers.
I just remembered Roy's classic line from "The IT Crowd": "Have you try to turn it off and on again?"
Just like with the Cable company. Their answer to every issue is to reboot the box! Of course they say that even if you tell them that the error code says Hard Disk failure But most of the time it does the trick!