Computer crashing Prime95 blend test

[Elvin29]

For a while now while playing Civilization 5 and Dota 2 my computer has been crashing.
No error screen just frozen mouse.

To try and identify the problem I tried to recreate the crash with stress tests.

I've run Prime95's blend test and that seems to instantly cause my computer to crash.
This leads me to believe its a memory problem, however, I ran memtest for a full pass and it didn't seem to raise any errors.

My power supply is 4 months old I bought it because I believed it would solve the problem so I know its not that. I'm lost here I have no idea what it could be, my only option is to leave memtest on overnight to see if I can get anything. If memtest shows up empty I'll get a new hard drive in hopes to fix the problem. If anyone has any ideas or a suggestions to try and solve the problem it would be greatly appreciated.

Specs
Dxdiag screenshot:

CPU: Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
GPU: NVIDIA GeForce GTX 970

Other tests I've run include
Furmark GPU stress test
http://www.ozone3d.net/gpudb/score.php?which=349479 - No Crash

Furmark CPU burner
up to 80°C n - No Crash

HD Tune
Error scan No damaged blocks No Crash

 

[Paul NZ]

Update the BIOS if it's not up to date. Do it in the BIOS

 

[rgd1101]

Prime95 blend test, isn't that a cpu test?
what temps when you running the test and when you playing those 2 games?

And the make and model of the new psu?

 

[dextermat]

Do not update BIOS since it was working before (doing so might fail and kill the motherboard)
How old is your gear,

Did you monitor your CPU / GPU temperatures
Download Hard disk sentinel trial to monitor the health of your drive
What brand and wattage is your PSU?

 

[Paul NZ]

If it supports crashfree or BIOS flashback that will fix it. Why would it kill it unless you have no idea what youre doing

 

[rgd1101]

My rule for bios update only as a last resort

 

[Elvin29]

Update the BIOS if it's not up to date. Do it in the BIOS

I can run the blend test without freezing now thank you very much. I'll have to try playing some dota games but I believe its fixed now. I can't believe I overlooked something like that again THANK YOU

 

[Multipack]

Be v careful which version of Prime95 you use (see section 12) http://www.tomshardware.co.uk/forum/id-1800828/intel-temperature-guide.html

 

[Elvin29]

Do not update BIOS since it was working before (doing so might fail and kill the motherboard)
How old is your gear,

Did you monitor your CPU / GPU temperatures
Download Hard disk sentinel trial to monitor the health of your drive
What brand and wattage is your PSU?

It still doesn't make sense to me that without a bios update a computer could deteriorate to the point at which it freezes constantly but i'm fairly certain that was the problem