Fix for computer hanging issue

I would be grateful for some assistance in diagnosing my computers problems. About 1 week ago I had a freeze when the computer went into sleep mode, I didnt realise it was a freeze as the computer just completely turned off, requiring the power button to restart instead of the normal keyboard wake system windows 10 uses. Now 3 days ago I have started getting freezes while using the computer. The symptoms are the monitor freezes, keyboard is unresponsive (num lock does not toggle, keyboard commands appear to do nothing), power button quick press does not work but full 4 second hold does force the computer off. After about 1 - 3 minutes the computer turns itself off. I do not hear any shutdown noise but its impossible to tell if that system is frozen or not.

DirectX Diagnostic is attached

Steps I have taken: 
- Update graphics driver

- Remove second monitor, second hard drive, external HD's and USB connections for powering devices like phones and game controllers.
- Clean computer of dust, which also necessitated replacing the CPU's thermal paste.

Removing the secondary hard drive seemed to prevent crashes for a few hours but it just froze playing Stellaris again.

I’m working at best buy geek squad phone number as computer repair agent. So you can trust and try out these steps and your computer hanging issue will be fixed on your laptop or desktop.