Lois-
Thanks for this latest update. Unfortunately when I attempted to install the beta driver on my D34010WYK NUC running Win8.1 x64, only the Intel Display Audio driver successfully installed, and the installer quit with an error saying 'one or more device drivers weren't installed'. I tried uninstalling the old drivers and reinstalling the beta with the same result, uninstalling from the Device Manager whilst marking 'delete all driver software' and reinstalling, and then tried uninstalling, running DDU in safe mode, and reinstalling the beta. Same result each time.
I'm glad that we have some kind of explanation, though, for why this has been happening:
"This beta driver addresses issues with Intel® NUC products with the 4th generation Intel® Core™ processors use Intel® HD graphics initially targeted for mobile devices such as Ultrabooks™. These Intel® NUC models cannot be accessed remotely when they are booted up without a monitor attached, also known as "headless" mode. Certain remote client software showed a black screen."
So while I'm disappointed that the drivers wouldn't install and have reverted back to the latest stable drivers, I'm looking forward to finally solving this issue soon...
ED: I have also tried installing the beta driver 'the manual way' via Device Manager >> Update Driver Software >> Browse >> Let me pick >> Intel HD Graphics Family (select) >> Have Disk, and got the following error:
I'm not sure if this means 7zip didn't unzip the file properly, if the download was corrupted (I downloaded the win64 zip file twice and got this twice), or if there's something wrong with the source zip. One other person here seems to have successfully installed, so I'm a bit clueless...