Sorry for bringing up the old topic, but today I've experienced the same thing with NetInstall 7.20.8 and Win10 - I've got to the point where I enter NetBoot IP - after clicking OK, it freezes. Tried 2 computers, admin mode, win7 compatibility mode, other interfaces off and on - no luck.
Thanks!
I've tried also 7.22.1 - still no difference, freezes in the same place.
I've got one router that would stay forever at “Authenticating” when trying to connect via Winbox, maybe there is different way to get it back to life?