Thanks for joining the NUC community.
This problem does not appear to be an issue with the NUC, please try updating NUC BIOS from the link below:
File name: WYLPT10H.86A.0030.EB.EXE
Are you able to play those files without AVR?
Please check the list tested peripherals here:
If I make a clean install of windows 7 - fully updated via microsoft update - without Intel's Graphics / HDMI audio drivers - and just use Microsofts generic drivers I can play the files!
By using the generic drives, I can't play HD formats like DTS-HD.
By the way it would not make much sense to play the files without the AVR ;-)
I have downloaded and installed the latest BIOS: from the web site (date 09-19-2014) I think that is the one you refer to?
Units for sound and video: