Today I decided to do my tests on Windows Server 2012 and I won’t say anything about it till I am completely done but I came across something that should be pretty handy to anyone who seeks this post :-).

If you’re trying to add the Hyper-V role to your Windows Server 2012 while hosted as a VM under VMware Workstation 8/9 you will need to do the following:

1. Shutdown the VM and close it from the VMs tab.
2. Locate the path to the VMX configuration file.
3. Open the VMX file and add this line at the end of it (hypervisor.cpuid.v0 = “FALSE“)without quotes this will get you past the (Hyper-V cannot be installed: A hypervisor is already running.) error message.
4. Now another entry needs to be added (mce.enable = “TRUE”) other wise you will end up with a HAL_Memory_Allocation upon start-up.
5. Save the VMX file and power on your VM.

I also had to use (vhv.enable = “TRUE”) to get VT to pass through. (Using Fusion on a MAC)

Now use the above at your own risk, please take a look at this post