VirtualBox - Cannot Register the Hard Disk

Environment
  • VirtualBox 2.1.2
Introduction
Get this error, when the hard disk is copied the one using.

Solutions
Each hard disk should have the unique UUID, therefore, change this via VBoxManage
C:\Sun\xVM VirtualBox\VBoxManage internalcommands setvdiuuid "D:\Virtual Machines\Windows Server 2003\H2 - Windows Server 2003.vmdk