Brian Cryer

Cry about...
Windows Hyper-V-Server

Virtual machine fails to start with General access denied error / Account does not have sufficient privilege to open attachment

When trying to start a virtual machine for the first time after copying (or replacing) its virtual hard drive file (.vhd or .vhdx) the virtual machine fails to start with the following error:

(x) An error occurred while attempting to start the selected virtual machine(s).

'PC-Name; failed to start.

Microsoft Emulated IDE Controller (Instance ID XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX): Failed to Power on with Error 'General access denied error'.

IDE/ATAPI Account does not have sufficient privilege to open attachment 'E:\Hyper-V\PC-Name\Virtual Hard Disks\MyVHD.vhdx'. Error: 'General access denied error'.

Where 'PC-Name' is the name of the virtual PC, the instance ID will be a unique series of letters and MyVHDX.vhdx will be the name (and path) of your own virtual hard drive file.

Causes

Each virtual machine is started using a virtual machine account. The virtual machine account needs read and write access to the .vhd/.vhdx file, but if the file has just been copied from somewhere then it most likely lacks the necessary file permissions.

Remedy

  1. If you don't already have the Hyper-V Manager error dialog open ("An error occurred while attempting to start the selected virtual machine(s) ...") then try to start the virtual machine now. You need the error open.
  2. Click "See details". This will show additional details, and will look something like:

    'PC-Name' failed to start. (Virtual machine ID B9C4F7D4-0009-4BE2-90FB-9D60B1A06BDD)

    'PC-Name' Microsoft Emulated IDE Controller (Instance ID XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX): Failed to Power on with Error 'General access denied error' (0x80070005). (Virtual machine ID B9C4F7D4-0009-4BE2-90FB-9D60B1A06BDD)

    'PC-Name': IDE/ATAPI Account does not have sufficient privilege to open attachment 'E:\Hyper-V\PC-Name\Virtual Hard Disks\MyVHD.vhdx'. Error: 'General access denied error' (0x80070005). (Virtual machine ID B9C4F7D4-0009-4BE2-90FB-9D60B1A06BDD)

    'PC-Name': Hyper-V Virtual Machine Management service Account does not have sufficient privolege to open attachment 'E:\Hyper-V\PC-Name\Virtual Hard Disks\MyVHD.vhdx'. Error: 'General access denied error' (0x80070005). (Virtual machine ID B9C4F7D4-0009-4BE2-90FB-9D60B1A06BDD)

    Where PC-Name will be the name of your virtual PC. The long sequence of letters and numbers (in my case above "B9C4F7D4-0009-4BE2-90FB-9D60B1A06BDD") is the Virtual Machine ID. This number is significant and you need it to fix the problem.

  3. On the host server open an elevated command prompt.
  4. Enter the following:

    icacls "full-path-to-vhd-or-vhdx-file" /grant "NT VIRTUAL MACHINE\Virtual-Machine-ID":(F)

    substituting the path to the vhd/vhdx file - you can obtain this from the original error message, and the Virtual-Machine-ID that you obtained from the "See details" part of the error.

    So the line for me was:

    icacls "E:\Hyper-V\PC-Name\Virtual Hard Disks\MyVHD.vhdx" /grant "NT VIRTUAL MACHINE\B9C4F7D4-0009-4BE2-90FB-9D60B1A06BDD":(F)

    But the path and Virtual Machine ID will be different to mine.

    If you get the message "Failed processing 1 files" then check the virtual machine ID.

  5. Now try to start the virtual machine. The error should no longer be present.

About the author: is a dedicated software developer and webmaster. For his day job he develops websites and desktop applications as well as providing IT services. He moonlights as a technical author and consultant.