In order to move vdi and image file to another location, change the following (highlighted in bold) in VirtualBox.xml to reflect it (no changes in uuid is required)

<MachineRegistry>

<MachineEntry uuid=“{5bababfa-ad62-471c-44b8-24bc07022f03}” src=“Machines/winXP/winXP.xml”/>

<DiskRegistry>

<HardDisks>

<HardDisk uuid=“{xxx}” type=“normal”>

<VirtualDiskImage filePath=“/media/software/virtualBox/winXP/winXP.vdi”/>

<DiffHardDisk uuid=“{xxx}”>

<VirtualDiskImage filePath=“/media/Software/VirtualBox/Machines/winXP/Snapshots/{xxx}.vdi”/>