Windows 7 Random Freezing, Have to Force Shutdown

So for the past month or so my computer has been periodically freezing, sometimes half an hour after start up and other times it can be fine for a full day of use. The freezing leaves my computer in a fully unresponsive state (pressing caps locks on my keyboard does not light up the LED. Internal LEDs and fans still run) and the only option I have is to restart it by holding down the power button.

I've tried several things after browsing several forums, the things I've tried include:
- Testing for bad RAM, test come back fine and as a further measure I have taken one stick out and tried using just one but I crash, same for the other stick
- Updating all Link Removed
- Checking for malware (using malware bytes) and a general virus scan (Trend micro Titanium)
- Scanning and fixing registry errors (using CCleaner) (this seemed to do the job as I was able to run perfectly fine for several hours, but then my PC froze
- Monitoring heat/CPU usage (the highest any component gets to is 45C at the time of freezing. Physical memory used at the time of freezing never exceeds 23%)

I'm not sure if there is any relation but it generally only happens while running Google Chrome, Hearthstone and Dayz. Yet I can play Guild Wars 2 (known to be very CPU intensive) for 6+ hours and have no freezing occur (same for most steam games)

Any and all help is very much appreciated, as freezing occurring with University assignments quickly approaching is not going to be fun.