14 November 2015

Re-enabling the Hanselman trick to easily switch between Hyper-V and VirtualBox after Windows 10 Fall update

Since my first forays into Xamarin I have been making great use of this awesome trick by Scott Hanselman to quickly change from a configuration with Hyper-V (for Windows Phone and Windows 10 Mobile development) and Virtual Box (for using emulators based upon VirtualBox. I created this dual-boot option in Windows 8.1, and it survived the upgrade to Windows 10 RTM 10240 in July.

After updating to the Windows 10 Fall update (aka 1511, aka 10586.3) I found out I had two boot option in my boot screen - "Windows 10" and "Windows 10", both with Hyper-V enabled.

Bummer.

Fortunately, this is easy to fix.

  1. Open an admin command prompt
  2. Enter bcdedit.
    You will get a list of three entries, the first one "Windows Boot Manager" (ignore that) and two called "Windows Boot Loader"
  3. Check that both have an entry "hypervisorlaunchtype" set to "Auto"
  4. Both boot loaders description "Windows10" and will have an identifier. One will be a {current}, the other a GUID like identifier, like {3bca20f3-367f-11e5-9da7-f5ee60b7b905}. That is the one you can change.
  5. Enter bcdedit /set {your-guid-here} description "No Hyper-V"
  6. Enter  bcdedit /set {your-guid-here} hypervisorlaunchtype off

If your reboot now, you will once again have two options, one with description Hyper-V, the other still called Windows 10

Caveat emptor: playing around with the boot editor can seriously mess up your system. Be sure of what you are doing. Even I usually stay away from this as much as possible. Worked on my machine - I cannot accept any responsibility for it not working on yours :)

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