OK sylvia_intel you have had weeks to "check with engineers", recommend BIOS upgrades and explain how to install the latest graphics drivers. The time has come to tell the whole Intel NUC community that (albeit regrettably) they have been duped. None of the current range of NUC's in fact support 4K output. The best you can hope for is 4K at 30Hz.
I guess I will keep bumping this thread to make sure that it remains near the top so that poor unsuspecting buyers don't waste their money if they are looking for HTPC quality 4K.
Perhaps it is also time that I start separate threads on the Win 8.1 memory (and Win 7 it seems) error messages for headless NUC's since I think I started that thread months ago. And then there is the USB 3.0 boot errors that were meant to be fixed by 3 successive BIOS upgrades. Not to forget all the poor consumers who have failed to make reliable connections using unknown remote apps like TeamViewer, Splashtop etc etc.
Or, perhaps just one thread titled "Buyer beware, read this before spending any money".
Last chance Intel.