Hit Delete during bootup and go to integrated peripherals or something like that in the bios. Disable onboard video and then hit F10 and say "Y" to save and exit. That should disable the 3200 on board video.
The default Ubuntu mirrors are as fast as any torrent so I'd DL from there and burn fresh if you don't already have a LiveCD.
The default Ubuntu mirrors are as fast as any torrent so I'd DL from there and burn fresh if you don't already have a LiveCD.