If you have to ask how to un-overclock your system, if you don't know what overclocking is and you had to google it...
...You don't have an overclocked system. Unless perhaps you got it from a friend who built it for you, in which case you should go ask him.
Overclocking is done usually when you're first building a PC, by setting the jumper settings for the CPU higher than they "should be." On some mobos this is quite simple, on others it can be a little tricky. On jumperless mobos, it's impossible.
Re: How do I turn off Overclocking??
Threaded Mode