♠How to Fix VirtualBox “UUID already exists” Errors♦

If you’re running VirtualBox on a Windows computer, you’ll probably run into errors from time to time. When I migrated my virtual hard drives from one physical disk to another I ran into a permissions error. Apparently when Virtualbox creates a .vhd (or other format virtual hard drive) it bakes in a universally unique identifier that it uses to recognize VHDs. Normally it doesn’t cause problems, but in this case it prevents duplicates or moved virtual disks from running from an unknown location.
The error looks like this:

“Failed to open the hard disk E:\VirtualBox VMs\Windows 8 \Windows 8 Enterprise2.vhd.
Cannot register the hard disk ‘E:\VirtualBox VMs\Windows 8 \Windows 8 Enterprise2.vhd’ {ca2bdc6a-a487-4e57-9fcd-509d0c31d86d} because a hard disk ‘E:\VirtualBox VMs\Windows 8 Enterprise\Windows 8 Enterprise2.vhd’ with UUID {ca2bdc6a-a487-4e57-9fcd-509d0c31d86d} already exists.
Result Code:
E_INVALIDARG (0x80070057)
Component:
VirtualBox
Interface:
IVirtualBox {3b2f08eb-b810-4715-bee0-bb06b9880ad2}
Callee RC:
VBOX_E_OBJECT_NOT_FOUND (0x80BB0001)”

Oracle has a chapter in the VirtualBox manual that covers UUID problems, which may reveal how to fix this. Or you can just follow the steps below.

How to Reset the UUID

To fix this you’ll need to run some text commands. Open up the Command Prompt. In both Windows 8 and Windows 7 it can be found by typing “cmd” into the Start Menu search box.

Now change the cmd prompt’s directory to the folder you installed VirtualBox in. If you put it in the default the command is this:

cd C:\Program Files\Oracle\VirtualBox\

Now type in the following command (or copy/paste using right click):

VBOXMANAGE.EXE internalcommands sethduuid “pathtovhdfile”

If everything worked you should see a message saying “UUID change to: …” and then the VirtualBox should work. All fixed!