Clone HD @ virtual box

Copy the disk and paste it.

1. Set a new UUID for the cloned disk, e.g.
   
   "C:\Program Files\Sun\xVM VirtualBox\VBoxManage.exe" internalcommands sethduuid hdb.vdi
2. Manually add this newly cloned disk image though VirtualBox "Virtual Media Manager".
3. Create a new guest profile as old system, and point the primary harddisk to your newly cloned disk image.

via http://edin.no-ip.com/content/clone-virtualbox-disk-image-ms-windows-mini-howto