BSOD: Machine Check Exception (caused by hal.dll)

I did yesterday, and the pins on the CPU looked fine to me (I looked up pics on Google and compared), and also the socket looked fine (I compared it with pics of the same MOBO on Google as well). I use Gammaxx Deepcool 400 (it's pretty good, it keeps the CPU at 32ish° Celsius while it's idle)... I fear I cannot use that tool since my PC now won't even boot. I had submitted my specs when I registered to this site, but if you need them, I can just type them here:

CPU: I5-6600K
Motherboard: Z170 Pro Gaming Aura
PSU: EVGA G2L 850W
GPU: MSI Radeon RX 480 8GB
SSD: Samsung 850 Evo
Optical Drive: Asus Blu-ray BC12B1ST
UPS: Cyberpower 1500 VA 900W
Heatsink: Gammaxx Deepcool 400

The case is a Full-Tower case and has plenty of space for air flow.

Is there a chance that if the heatsink is not making good contact, or it's somehow loose, that itself could be the cause of the crashes?

Yes, I did. Sorry for taking so long to reply, I work a lot. So yeah, I did replace it the right way, but to me it doesn't feel as tight as the first time I placed it (when I built the computer), so I thought that maybe "making and not making contact" could make the processor (somehow) wanna stop working. Just an idea I had to try to explain what to me still makes no sense; I mean, it worked perfectly fine in Safe Mode for a whole week, until I decided to use the epsxe (Playstation 1) emulator. Now it won't even boot and freezes in BIOS.

I do know exactly where I dropped the screw and where exactly made contact with the motherboard, I could take a picture and edit it, drawing an arrow pointing at the specific spot where the screw hit as soon as I get home, to then upload it into this thread, if that is possible.

I had similar situation to you. I was playing a game on the Windows 10 and the system was crashed. And I got reboot loop and blue screen frequently. Then, when I try to install a new fresh Windows 10 from DVD/USB, it causes blue screen error during install. And the errors are something different each time. e.g. "driver irql not less or equal " or "attempted execute of noexecute memory". I replaced the motherboard and RAM, but it still does not change anything. I suspect it's the problem of CPU or the power supply. But I currently do not have the CPU or PSU replacement to try. My machine was built 8 months ago, it's also quite new.

Attachment 135034

There is the pic. The screw hit somewhere around there. No, I get no beeps (would have mentioned it if I did, but I appreciate the question). Thanks for wanting to help me, and once again I apologize for the late replies... Could you take a look at the pins in the socket? They look messy to me now that I took a close look at them, and to me they kinda look different to the ones I see on Google Images, but I have zero experience regarding CPU pins, so I would like you to tell me if that is the problem.

I have been trying to upload a sharper picture since last night, and for some reason it just won't let me. Is there a limit per day or something like that? Anyway, I will keep trying, but if it still doesn't work, I will go back home (in few hours) and I will try from my laptop. Thanks for your patience and for your will to help me.