I appreciate Win7 isn't supported but I believe it has been possible to get it running. Indeed, Intel themselves said so.
I just need USB drivers to try.
Before I found what the problem, I was able to clone my current Win7 setup onto a SSD and install it in the NUC. Win7 started and I got Desktop icons showing - but no mouse or keyboard.
" Indeed, Intel themselves said so."
Sure,on NUCs with 6th gen processors or lower.
Windows 7 is dead. Just upgrade to Windows 10 and problem solved. There is no good reason to stay on windows 7, and use the argument that some applications do not work on Windows 10.
If you want to debate this, do so on the Microsoft forums. This is not a NUC issue. It is a processor issue, and Microsoft made the rule.