Hi Des_Zac
surely we are straying off the issue. lol
Anyway. As its ubuntu you can run it as a live CD if you wish. By the sound of your original post, that would be sort of what you were trying to do.
Not really understanding what you want to do really though, if you just want a new HDD to have ubuntu on it. Burn the ubuntu ISO to a disc (burn it as an ISO, use a burning program, like ashampoo burning studio free, my personal favourite
)
and then, put the new HDD into the computer you want to use it in,
and then, on that computer, put the ubuntu CD into the CD drive and boot from it (either using the boot menu by pressing F8 or equiv at boot, or by changing the boot order in the BIOS) and install to that HDD.