Virtual Box Fails after installing WP8 SDK

After installing the WP8 SDK I round that I couldn't open my VBox VMs any more. I was getting the error:

VT-x is not available. (VERR_VMX_NO_VMX)

 Result Code: E_FAIL (0x80004005) Component: Console Interface: IConsole {db7ab4ca-2a3f-4183-9243-c1208da92392}

It was completely unexpected because i had the WP7 SDK installed and everything was working fine.

Looks like the new SDK needs Hyper-V to run the emulators and having the Hyper-V services initiated won't let Virtual Box use the virtualization hardware.

The solution is a quick and dirty:

bcdedit /set hypervisorlaunchtype off

And a restart to be able to work with your VBox again.

If you want to start your Hyper-V services again you just have to run

bcdedit /set hypervisorlaunchtype auto

And restart.

After saving what I was doing I have converted the vdi to vhdx and started using Hyper-V for my development virtual machine. Now I feel less heretic.