I have a dual-boot system, Windows 7 on my C: drive and Server 2008 R2 on my K: drive. Two separate hard drives.
I set up Hyper-V and everything was running great, building VMs left and right and loving life. My Win7 drive became corrupt and i blew it away and reinstalled windows 7. In my Server env, I couldn't start any VMs because "hypervisor is not running". I ran bcdedit /set hypervisorlaunchtype auto and that fixed my problem.
I booted into Windows 7 and used that for a few days. No problems. Booted into Server 2008 R2 today and I get the same error
"The virtual machine could not be started because the hypervisor is not running."
No recent messages in the Hyper-V-Hypervisor Operational log. Only recent error in the Hyper-V-VMMS Admin log is following:
'Hypervisor' driver required by the Virtual Machine Management service
is not installed or disabled. Check your settings or try reinstalling
the Hyper-V role.
I don't see any other relevant messages in other Hyper-V-* event logs.
I checked the %systemdrive%\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines\ folder and it's chock full of symlinks to virtual machine config files, which one blog entry mentioned as a possible issue.
I'm at my whit's end, not sure what else to do. Virtualization is enabled in BIOS, relevant services are started, etc. Any ideas?
Resolution:
I had to re-apply the set hypervisorlaunch flag, and then I turned my machine off and physically unplugged the machine's power supply and then rebooted. Hypervisor worked fine after that. This is a consistent fix. If I just re-apply the flag without unplugging, it doesn't work. I must say, I dread booting into Win7.
Think my problems will go away when Windows 8 comes out w/ Hypervisor on the client OS?
Best Answer
In the spirit of Don’t Be Afraid to Use The Science, I just tried this, by dual-booting away from Windows Server 2008 R2, and it looks like when you install the other OS, it goes and disables a few of the extra flags in the bcd store.
When you're in 2008 R2, run the following from an elevated command prompt:
bcdedit /set hypervisorlaunchtype autoThis should put the Hyper-V driver back into the launch procedure and you should be able to start your VM's again.