Started having random freezes on my computer for no apparent reason

[Bisop]

A few weeks ago I started having freezes on my computer, a couple of times per hour, lasting one minute, usually while playing demanding video games.
Sometimes it would give me the blue screen of death followed by an error claiming it was unable to find boot device, the only solution being to restart the PC which would fix the error.
Recently however the freezes started to be more common, sometimes causing the computer to crash during boot-up and restart.
Whenever a freeze occurs I can hear a fan stopping and restarting, however I cannot determine which fan it is, I suspect the problem may be caused by the psu or the hdd.
I have excluded heat problems as the temperatures are under 60C (for the cpu and graphics card) when the freezes happen and used SeaTools to run a short check on my hdd which yielded no problems. Haven't used a long test as it said it might damage my data.

My specs:
I5-4690 @ 3.50 Ghz
DDR3 8gb of ram
Nvidia geforce gtx 770
Seagate Barracuda 2TBk
Kissquiet 620W psu

 

[ThrashZone]

Hi and welcome to SevenForums,
What utility did you use to gauge the temperatures ?
60c isn't all that good
Download Real Temp 3.70 | techPowerUp

http://www.sevenforums.com/bsod-help-support/96879-blue-screen-death-bsod-posting-instructions.html

 

[Bisop]

Thanks for the welcome, I used Speccy to check the temperature.
I thought 60C was an acceptable temperature when running a newer game on a gtx 770 :S, I did open my PC case and cleaned everything of dust to reduce the risk of overheating.

 

[ThrashZone]

Hi,
Take a snap shot of the cpu cool that is where all of the dust collects
Take an other of the rest of the case opened too to get a general idea of air flow.

 

[Bisop]

Uhm I don't really understand you're asking me to do, basically take a picture of the PC right?

As a small update I left my PC case opened and the temperature was around 45C for both the CPU and graphics crash when the freeze happened.