I want to show you how to fix an Hyper-V validation error that may occur when Installing this Server Role on a Virtual Machine. I’ve stumbled upon this error when trying to install and configure Hyper-V on a VMware Server and after searching for a while I’ve discovered the solution for this problem. The wizard displayed the following error “Hyper-V cannot be installed: A hypervisor is already running” when using Server Manager Console:
The first thing you must do is to shutdown the virtual machine because we need to modify its configuration file. Open Powershell and type shutdown /s /t 0 to turn off the Server immediately. Navigate to the VM’s location and open the *.vmx file using your favorite text editor:
At the end of the file we’ll need to add the following lines:
hypervisor.cpuid.v0 = “FALSE” – informs the OS that is being hosted on a Virtual Machine. The Hyper-V Installation will verify if the Server runs of a Virtual Machine so this setting must be added
mce.enable = “TRUE” – enables Machine Check Exception (MCE) which is used to detect CPU hardware errors. You can read more about MCE on Wikipedia.
vhu.enable = “TRUE” – enables Nested virtualization
Once the lines have been added, save and close the file
There is one more thing we need to configure. Open the VM’s Settings page, navigate to the Processors section and enable the following features:
Virtualize Intel VT-x/EPT or AMD-V/RVI.
Virtualize CPU Performance counters.
Once you power on your Server, you should be able to install Hyper-V without problems. Hope this article will serve you well in fixing this Hyper-V installation eror. Wish you all the best and stay tuned for the following articles.