PC randomly shuts off

[Illuminatis]

I just built this PC last week, and since the first day it has been randomly shutting itself off. Am I correct in thinking it is most likely the power supply? Also for some odd reason the safely remove hardware icon is showing my sata drive in there, could that be causing this problem?
These are my specs if it helps: http://secure.newegg.com/NewVersion/wishlist/PublicWishDetail.asp?WishListNumber=5482688

 

[Abarbarian]

You might find something to help you here ,

https://www.pcreview.co.uk/forums/thread-2697599.php

Everest Home edition has some tools that will stresss your memory , HDD and CPU and that might narrow down whats wrong .
Memtest will tell you if your memory is faulty .
Those are the only ones I've tried so far .