Complete system freeze

Hello all,

So I have built a new system, Thus far it has completely froze 4 times in the last 24 hours, it will freeze up and I wouldn't be able to do anything other then hit the reset button, once windows starts back up I don't get any event logs or any other log to find out what caused the problem.
The things I was doing when it crashed;

first time, downloading 3dmark vantage
second time, loading up ncix.com
third time, loading up windows live mail
forth, listening to music setting up my 5.1 speakers.

Temps under load with prime 95,


Specs:
Asus p7p55d
I5 750
G.skill ripjaws PC3-12800 2x2gb
Asus 8800Gt
Corsair TX550W
80gb Maxtor Hd

So anyone have any idea what might cause this? Im thinking it may be hard drive related but im looking for more opinions, thanks

i am not sure with the i5/7 systems, but 70c seems extremely hot to me. I haven't seen those temps since the old P4 Prescot days.

Well from what I have read temps below 75c should be fine, while i agree my temps are high with this stock intel Hsf, But I dont think temps are the cause, since at idle (nearly idle) I have frozen up.
It just happened afew mins ago again while I was compressing a bunch of pictures into a winrar archive.
I looked around in my bios, everything is at stock, well it was, my ram was running at 1.6v which its stock is suppose to be at 1.5v, so I set it at 1.5v, Would that have caused this issue?

Edit:
the voltages listed in my bios, I know they are not always the same for others, but do these look right?
Cpu 1.216
Imc 1.103
Dram 1.50 (was at 1.60)
Cpu ppl 1.800
Pch 1.05

Edit 2:
Ran Memtest for awhile and it found no errors

I have a i5 and those temps look fine. As for voltages on ram, its my understanding that raising the ram voltages are not like they used to be. Everything I am reading now says put ram at factory specified voltages.

I still recieve the random freezes, I have a new hard drive on the way to see if that is the cause, other then that I'm not sure what else it can be, I have tried afew new sata cables, also tried using different sata ports, even tried the 1 port the jmicron sata controller offers.
So i take it no other ideas anyone?

Try bumping the Vcore up to about 1.250V in the BIOS (+.03V).