“Unnamed VM” Failed to Initialize

Recently, I am testing out the Microsoft Hyper-V on a test computer. Once I did the Microsoft Server 2008 updates, it mess up all my virtual machine installed on the server. I am getting the following error message : “Unnamed VM Failed to Initialize” whenever I tried to start a VM. It also deleted all my virtual NICs that I have created.

The only solution I found on the web is to give “Full Control” rights to the ‘Virtual Machine’ user for the “C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines” directory. This directory is hidden, so in order to see it, you will need to change your view to show hidden files.