System random resetting

Hardware Hub PSU
1

So, here's the deal:

My computer randomly reboots itself after the first appearance of BIOS logo. This happens every maybe around 50th time I restart my computer and there is no apparent reason for that. 

My computer has been doing the same thing ever after I've got the thing.

 

Other odd thing that keeps repeating itself at random points, is that windows gets stuck in the "Starting Windows" - screen. That occurs also around every 50th restart. Never at the same time as the restart-reset happens.

I hope you can get something out from this post, and maybe give me some aspects, why these two things keep happening.

2

Try booting a linux distro onto a usb, run it, and then run memtest86 to see if your ram is the problem. 

3

Ran the memtest86, no errors in the results.

I am kind of starting to lean to that conclusion that my CPU (i7 2600k), doesn't want my RAM to run at 1600Mhz, and resets the memory to 1333Mhz, by force shutting the PC.

Then again that doesn't make sense either, because the reset only happens ever so seldom.