A few things you may need to tell us in order to get help.
Does this occur with certain programs running (games, editing software)?
Do you have high cpu, disk or memory usage?
Have you overclocked your computer?
Are your components overheating? (You can check this in programs like open hardware monitor or msi afterburner to name a couple.)
openhardwaremonitor.org
If you can get video or pictures of this occuring it would be much appreciated.