Last modified at 5/5/2014 3:34 PM by Koen Zomers
If you're copying a VHD to use it for another virtual instance on the same machine, VirtualBox will display an error while trying to attach the new VHD stating that the disk UUID is already registered. To solve this problem, you can simply change the UUID of your copied VHD. Follow these steps to do so:

  1. Open a DOS command box
  2. Navigate to the path where you have installed VirtualBox (usually c:\program files\Oracle\VirtualBox)
  3. Execute the following command:

    vboxmanage internalcommands sethduuid "<full path to VHD>"


  4. This will change the UUID to a new random UUID. You will now be able to attach it to VirtualBox.