I installed Windows 10 using the official ISO and one of the serials I have with MSDN. When I reboot my Macbook Air 2013 it gets stuck on a black screen for around a minute and then start loading Windows. I only have a windows partition at the moment.
I tried resetting the NVRAM. Didn't help.
I followed the advice here but that didn't help either since it seems to be for Windows 7 only.