Update on the situation:

I used Memtest 4.00 to test the RAM, and it passed without a single error.

As I said earlier, the problem persists even after a fresh Windows install where nothing else was installed, other than some windows updates.

Regarding the whql certified drivers, as I said, I downloaded the drivers directly from the official website so I believe they qualify, but correct me if I'm wrong.

Are there any viruses that survive a full format by staying in the boot sector of a drive, or infecting the BIOS? Could that explain the issue? If so, how do I clean it?

ICould it be anything else? Like a fried mobo? Fried CPU? PSU going dead? Defective cables? I mean, if I had extras of these things, I'd try them out, but I don't, and it's a shame if I start buying stuff only to find the problem is still there

My last and final resort will be to build a whole new PC from scratch... but that's an expensive solution, which I really want avoid.