[ubuntu] Installing Ubuntu 12.10 on a computer with Lubuntu 12.10

Hey All,

Trying to install ubuntu on a computer with lubuntu, but my attempts with both a live dvd (since the ISO for ubuntu is too big for a cd) and a live usb have only ended in failure. When I try to boot from the usb, I keep getting an error saying no ISO found. For the dvd, I get "No media found". Is this related to having lubuntu on the hard drive?

I have no other OSs installed on the hard drive.

Thanks