New PC: Having Freezing Issues

[Zole_Zole_Zole]

Hi guys.

Recently I've built my own PC (first time), but since I completed it, it's had a problem;
Every few hours it will freeze, first the screen will freeze, then the mouse and music(if I have it on) will stop as well.
It will take about 20-50 seconds before it resumes.
Freezes will occur whenever; I could be playing wow, skyrim, civilization5 or even just using chrome to browse the net.
EDIT1: Sometimes the mouse will remain active throughout the freeze, but screen and sound will still stop.

Here are my components:
cpu; intel sandy bridge i7-2600 (3.4ghz)
ram; kingston 16gb ddr3 (1600mhz, 4x4gb)
hdd; 1tb seagate barracuda 7200 sata3
ssd; 120gb ocz vertex3 2.5"
gpu; evga geforce gtx580 ds (1.5gb)
psu; 850w
mobo; gigabyte z68xp-ud3r lga 1155
os; microsoft windows 7 64-bit

At first I thought it was a GPU issue, so I've updated the driver,but it has not resolved the issue.
If anybody could help/offer some advice, or ask for more info, I would be greatly appreciative.

EDIT2: The freezes are not always spaced a few hours apart; sometimes they will be more frequent and I will get 2 or 3 an hour.