There may be times when you’ll want to install the Hyper-V role on a VM running from within Hyper-V. When you go to install the Hyper-V role, you’ll likely get an error message:
“Hyper-V cannot be installed: A hypervisor is already running.”
That’s right – Hyper-V doesn’t like to be installed inside a VM running on Hyper-V. To get around this, you’ll have to use the DISM utility.
dism /online /enable-feature /featurename:Microsoft-Hyper-V
This will only install the Hyper-V role. It will not install the Hypver-V management tools.
This process had been tested on a Windows 2012 VM running on a Hyper-V 2012 host. This is provided with no guarantee and I assume no responsibility for the use or misuse of this process or any issues resulting from its use.