Windows 10: Frequent BSOD, several different error messages

My system has been experiencing frequent BSOD for the last several weeks. Several different messages occur:

WHEA_UNCORRECTABLE_ERROR
IRQL_NOT_LESS_OR_EQUAL
KMODE_EXCEPTION_NOT_HANDLED (FLTMGR.SYS)
APC INDEX MISMATCH


Latest Minidump Files are from a month ago. Can't find minidumps or Memory.dmp files from crashes over the last few days. The system was configured to create them but they're not there. Previous files, system info and Memory Test results are here:
https://1drv.ms/u/s!As_wCEwvboBnjBcHqIm8VtAoZl-c


Tried:
Updating BIOS
Updating Chipset driver and all other drivers using Driver Reviver
Uninstalling & reinstalling Firefox
Memory Test
Re-registering time service
Fixed error 10016 error
Windows update: these keep failing, even from standalone updates:
Feature update to Windows 10, version 1809
2019-02 Cumulative Update for Windows 10 Version 1803 for x64-based Systems (KB4487017)


Is it a hardware issue? Tried calling manufacturer (Asus) but they were not at all helpful, blamed software without even trying to diagnose.

:)

 

Frequent and random appearing BSOD 'internal power error'.


Here are the magician screenshots:

Disk Drive




SMART button:










These tests didn't take long. Perhaps I missed a checkbox?

Also good to mention, I always get this message when starting " Samsung Magician":




I installed the SSD drive during Christmas 2016. I tried different drivers etc, but this message always came back.
As my PC worked perfectly at that time, I let it rest in the end and used the lastest microsoft driver that windows update installed.

As to the steps in post #22. I did not yet executed these steps, so I cannot give you an update just yet.
I hesitate a bit, because they seem to bring me in a new level of computer repair&analysis - into an area that is new to me. A bit out of my "comfort zone", and I need time to familiarize myself with these enhanced steps, so that I feel myself capable enough of doing them, without fearing to screw up my PC. Please give me some time for this. I will try to do this during this weekend.

I also didn't come round into doing steps 10 and 11 from post #8. Should I still do these?

 

Frequent and random appearing BSOD 'internal power error'.


Update:
I did steps 6 and 7:

BIOS reset. I choose the 'optimized defaults':







And then I did steps 8 through 11.

Next step is the memtest86+. I created a bootable DVD, and tested if it works. (It does.) I plan these memory-tests the coming nights.
However, I can't see how I can test every SDRAM module separately. How do I do that?

(NB: After closing my game yesterday, I got the first BSOD in weeks, with a (new) message: "reference by pointer".)

 

Frequent and random appearing BSOD 'internal power error'.


I first did step 7:
I downloaded avastclear with the link provided. According to the instruction on the avast site, I rebooted in safe mode and started avastclear.exe

However:
After login, I got this [system error] message:




Then I starten avastclear and received these 2 error messages:




As this didn't work, I rebooted normally, and uninstalled avast the normal way with "add/remove programms".