Question Computer occasionally freezes

[Quintexial]

Particularly, the problem is, every so often, my computer will freeze in usually the following order: First, program stops responding to mouse clicks or hover - then, mouse locks up and screen is frozen (at this point, sound is usually still playing, and things such as microphones [i.e. in a voice call] still work) - next, sound stops and at this point computer is entirely unresponsive. An inconsistent amount of time (anywhere from 30 seconds to 5 minutes or more) later everything unfreezes - any inputs I did during the freezing (e.g. mouse clicks) then happen all at once.
Specs are as follows:
Motherboard: GA-H110M-A
CPU: i5-6600K
GPU: GTX 1660 Ti
Ram: Kingston HyperX Fury Black 8 GB (2 x 4 GB) DDR4-2133

The issues started happening soon after I upgraded to the i5-6600K from a previous CPU (I did try swapping back to the old CPU - did not resolve the issue) - at the same time I also installed a cooling fan/heatsink (Cooler Master Hyper 212 EVO). Since the freezes started happening I also upgraded from a previous GPU to the current one listed above.
I've updated the BIOS on the motherboard, which did not resolve the issue.

Edit: OS is Windows 10.

 

[rgd1101]

cpu/gpu temp and usage?
ram/ssd/hdd usage?
make and model of the psu?
malware scan the system?

 

[Quintexial]

cpu/gpu temp and usage?
ram/ssd/hdd usage?
make and model of the psu?
malware scan the system?

CPU/GPU temps are within normal levels, from what I can tell, and the usages for both doesn't spike when the freeze occurs.
The freeze happens inconsistently, apparently unrelated to what I'm doing at the time - it's just as likely to happen when I'm using my browser as it is when I'm playing a game.
PSU is EVGA 500 W 80+ Bronze.
And I've done malware scans, which have turned up no issues on that end.
Only thing I haven't checked prior is HDD usage, so next time a freeze happens I'll attempt to check that.
A final note: I've checked reliability monitor - most reports are somewhere along the line of 'stopped responding and was closed' or 'stopped working', and vary from the thing I was using at the time (e.g. firefox or the game I was playing at the time) to other windows processes. The most common process, it seems, in the reports is dwm.exe.