Error starting Hyper-V VM :

I decieded to delete the VHDX file of a Virtual machine and create a new. The purpose was to do a reinstall, and keep the old file incase I needed som files.

After creating the new VHDX file I tried to start the virtual machine and I got this error.

Event ID 12030 : Failed to start.

 This is no known user to me.

The Hyper-V console gives a descriptive error :

 Permission denied.

The only thing that have changed was the creation of a new vhdx file, so I checked the permissions of the VHDX file.

 This is the default permission for files in this folder.

Added the user acccount I saw in the eventviewer. This user account have the same username as the Virtual-Machine ID.

 I used ICACLS to add the permissions.

icacls “V:\vms\Virtual Hard Disks\2012web.vhdx” /grant “NT VIRTUAL MACHINE\18020765-68E5-4082-9439-F39BB26CB4C7:(r,w)”

 Permissions after I added the entry.

 

Hyper-V creates a local user for each Virtual-Machine as a Security precausion.