Backtrack:  
 
by lunarg on September 9th 2014, at 12:04

Shutdown the VM.

Open .vmx file with Notepad or another plain text editor.
Add these lines:

hypervisor.cpuid.v0 = "FALSE" 
mce.enable = "TRUE"
vhv.enable = "TRUE"
vpmc.enable = "TRUE"

Save and start the VM. Now you can install the Hyper-V role.