The Guarded Host feature (pictured below) allows us to run shielded VMs on Hyper-V with remote attestation. While uncommon on Windows 10, it can come up both in lab testing and developer scenarios in ultra-secure environments. In this case, a user noticed hibernation was disabled once the Guarded Host feature was enabled. What’s more, it would not come back through changing the normal settings.
I assume this may not have been true on previous versions of Windows 10, as in this case, Guarded Host was in use for some time on previous Wndows 10 builds.
Figure 1. Guarded Host setting in Windows Feature dialogue
It turns out there is a setting in the registry that appears to be added when you enable the Guarded Host feature is installed. Find the registry key:
Then, find the value GuardedHost, which will be set to 1 by default.
Change this value to 0 (the number zero) and reboot.
After reboot, hibernation will again be available.