Thanks for joining the NUC community.
Windows requires having a default audio output configured through Control Panel, checking the following setup might help:
Sound Playback is set to the wrong device
Go to Start > Control Panel > Sounds and Audio Devices, click Audio tab. Check the default device for sound playback; there can be multiple selections. Select the desired device, either rear panel or front panel.
thank you, but I solved it already. I already did what you proposed before and it did not work.
Than I reinstalled the graphics drivers from the latest complete driver package on your website - overwriting the Microsoft drivers that were autimatically installed. They were marked as "older" but I continued anyway.
Voila: I had sound, but only stereo.
So I had a closer look at the Itel driver section and discovered that the latest drivers in the complete package were not the latest. There were newer graphics drivers.
Installed them - and now I'm enjoying DTS and AC3. I only did not get the HD (Blu Ray) audio formats to work, but this might be too much to ask?