I downloaded the ubuntu-12.10-desktop-amd64.iso.
Then I created a bootable USB stick using the guide from here. I booted the USB stick and after the Ubuntu logo and some circles loaded beneath it, nothing happened.
So I went on to burn a DVD following these instructions. I booted the DVD and this error was rendered:
General error mounting filesystem A maintenance shell will now be started CONTROL-D will terminate this shell and reboot the system Give root password for maintenance (or type Control-D to continue)"
Why can't I run Ubuntu?