Custom build spits Machine_check_exceptions and Clock_watchdog_timeout

I read the first post again and now I've seen you've mentioned it before. My bad.

I've tried the intelburntest multiple times on increasing difficulty. All the tests passed.
I tried seatools. The short drive self test and short generic test all passed. While preforming long generic test, the pc crashed with a Machine Check Exception. I then started running the furmark test. It ran pretty well. The video card ran at around 60C. I could not finish the test though, because I got another MCE. While running furmark I was also running the seatool long generic test.
I not convinced it's the harddrive's fault, though. The harddrive has been in a previous pc with windows 10 and it never gave errors.

I'm now running Memtest again.

I read the troubleshooting guide. I have tried multiple configurations. All with the result of bsod's.
I just reinstalled windows 10 again, hoping that this might solve it.

Also, I've send an email to the shop I bought the pc if it might be still possible to return the motherboard and CPU.

Reinstall is so far successful. The PC has been stable for about 10h.
I'm hoping now that it was just a driver problem.