Hi, welcome to forum.
It can be an OS problem if you are using an old install but, it can be also high temps, bad RAM, bad PSU, bad drivers or corrupted BIOS.
If is the OS, a repair or fresh install will fix the problem;
If you have high temps, you should try to drop down them;
Update all the drivers and the BIOS file.
To check the RAM, run memtest86
' ">http://memtest86.com for several hours (overnight if you can);
Post the PSU brand, wattage and rails amperages (you can find the info in PSU's attached label) and post the system hardware too. Thanks.