When working with new technology, if you are like me you might like to setup virtual machines to learn the technology and its new features. I use VMware Workstation as my virtual machine hypervisor, installed on a Windows 7 laptop. With the release of Windows Server 2012 and the improvement in Hyper-V I wanted to setup a VM with Windows Server 2012 installed and then configure the Hyper-V role. Unfortunately ‘out-of-the-box’ Windows Server 2012 (or Windows Server 2008 R2) won’t let you do this as it detects the existence of another hypervisor.

The exact error is “Hyper-V cannot be installed: A hypervisor is already running”

In order to enable hyper-v on VMware Workstation you need to make a couple of small changes to the VM settings that will hide the fact the  Windows Server 2012 server is already installed on a VM.

Intel-VT or AMD-VT  should be enabled for the physical system

Edit the CPU settings of the VM and enable the Virtualize  Intel-x/EPT or AMD-V/RVI check box

You will also need to edit the configuration file of the VM and add the following line

hypervisor.cpuid.v0 = FALSE

This option hides the fact we have hypervisor within a hypervisor and will allow the hyper-v role to installed.

You can use the above process for both Windows Server 2012 and Windows Server 2008 R2