FX8320 is min spec for D2 (and seems it struggles going by some reviews), have they patched the memory leak yet, look in event viewer for Resource exhausted (i gave up on the demo).
Can't say for QC.
Not enough CPU power would result in bad performance and not as dramatic of crashes. The game ran fine before 2017 so it is not the CPU acting up. I did not experience this crash anywhere near as often as I do now. Even then, on games that really need a lot from the CPU like Mideval Engineers and Space Engineers I have not experienced any similar issues.
Log Name: Application
Source: Windows Error Reporting
Date: 6/19/2017 9:29:05 AM
Event ID: 1001
Task Category: None
Fault bucket , type 0
Event Name: AppHangB1
Response: Not available
Cab Id: 0
These files may be available here:
Rechecking for solution: 0
Report Id: b709500e-43bd-11e7-aa79-40167e7aeb1f
Report Status: 96
<Provider Name="Windows Error Reporting" />
<TimeCreated SystemTime="2017-06-19T16:29:05.479845500Z" />
This is an application event, that doesn't explain the hard reset. You need to look for a system crash event, in the Security and Maintenance section.
What motherboard are you using and with which BIOS version? Also, is the APU GPU enabled? If it is, try disabling it.