If the ISO isnt bootable you downloaded a bad copy of the Vista ISO from the torrent site you found it on. Cause all Vista ISO's from the Microsfot official sites are all bootable.
So you either can use Daemon tools to mount the ISO image and then use VLite or pirate yourself a better copy of Vista.
So you either can use Daemon tools to mount the ISO image and then use VLite or pirate yourself a better copy of Vista.