1) VBoxMange clonehd
2) Register it to VirtualBox (File|Virtual Media Manager|Add) create new VM and mounted clone drive
>> start's up but doesn't completely boot <<
How do I change UUID?Ubuntu is sometimes configured to mount a particular drive - identified by UUID - on boot. Your cloned drive must have a different UUID, otherwise you won't be able to register it on the same host as your original. That means you may need to fix the boot config. If Ubuntu is configured to boot from a particular IDE or SATA channel then that will not have changed and you won't see this problem.
Thanks
Danny