This is not the solution to the problem described and is an inaccurate statement.
Installing Windows with Secureboot turned on is absolutely supported. I've done this several times over. Additionally, in order to get the little sticker OEMs put on their computers indicating they're Windows 8 ready, they must ship with Secure
Boot on. Secure Boot requires UEFI mode for your firmware as well.
I've been building Gen2 VMs for more than a year now. It's only recently been an issue after upgrading to Win10 1803.
In my case, I remote into the Hyper-V host via RDP and I believe that the RDP session is just not presenting the display fast enough. There's no way I can tell to have the system post last a little longer. What helped me was the keyboard input
method in the Hyper-V settings. It still doesn't solve my problem, but allowed my keyboard inputs to register while the VM was turning on so that I could press any key before it timed out. I still never see the message but if I click and press
any key, ultimately it will boot. It may take a few times.
But to reiterate - you do NOT need to turn off Secure boot. In fact, you're reducing your security footprint and following bad practice by recommending people turn off security settings.
Don't answer questions like this as you could likely cause someone further issues with what they're trying to do. People need to be able to develop their images with all the functionality and security they plan on implementing in their production environment.
Can someone remove the answer on this? As far as I'm concerned, this is still an issue that many people face and turning off secure boot is not the answer.
nick
