Wow this one blindsided me this evening. I’ve just replaced the tiny 500gb drive in my main demo laptop with a shiny new 1TB one (I have a lot of VMs you know) and got hit with this error. Basically what I did to replace the drive was use the free software from Acronis that came as a download with my new Western Digital drive to clone my 500gb drive onto my 1TB drive, standard stuff. Having done that and trying to boot I got some lovely messages as as a result of doing boot to VHD and the the BCD no longer being able to find the files (because settings in the BCD had obviously changed) to fix that I ran some simple commands:
select vdisk e:myvhd.vhd
bcdboot <mounted vhd letter><vhdname.vhd>
And repeated for each of my bootable OSes. All was good the OSes were working, but when I got into Windows Server 2008 R2 I couldn’t start any VMs….a quick look at the System Event Log revield the error
Hyper-v launch aborted due to auto-launch being disabled in the registry
bcdedit /set hypervisorlaunchtype auto
Finally I was done and my machine was back to normal. Error fixed.