[rkut]

When does this freezing occur?

I've encountered this many times and usually it has been graphics card's or some device's driver's issue.
First make sure graphics card ( if you have a discrete one), memory, and cables to drives are correctly plugged in.
Make sure you are using correct and up-do-date drivers.

[Ekillz999]

Try this it may fix your problem: Open your PC and change the HDD cable to another SATA port. I had a similar issue with another PC, and switching the ports solved the problem.

[RƎDSPY]

Sorry OP, sounds more of a hardware problem than a software problem.

I'd advise you open the case of the computer and look for anything that's loose or nearly about to loose connectivity with something its attached to.

[Fireworks]

Do you have a 3rd Party or a Integrated GPU?