Windows 7 Random BSOD W7Hx64 when playing videos (DSPlayer/madVR/ffdshow/avisynth)

How old is the system? I wonder if age might have anything to do with it? If you really want to do some testing rather than waiting then you could try setting the overclock again and then running something like Prime95 to stress test the system.
This will let you know if it's stable or not.

I'd run the test for about an hour, monitoring temps as you go.
GIMPS - Free Prime95 software downloads - PrimeNet

Temp monitoring
HWiNFO, HWiNFO32/64 - Download

Oh and post any new dump files please.
System was built in April 2013, not that old.
I'll wait for any crash/BSOD without the OC :)
It would be so nice if it was the cause.
Moreover I don't really need the extra cpu power anymore, it's a remnant of my PC gaming days (over now, thanks to the PS4 :) )
Thanks for the update. I'll await your next post and hope all goes well.. :)