Not Windows 7... just Vista SP3 run through another Mojave Experiment: Convince hordes of people, who probably shouldn't be on networked computers, that Windows Vista is not Windows Vista...
Also: As far as I know Microsoft allows an upgrade disk to install a fresh copy, it will just request the media of a previous version to ensure that the upgrade is valid. Maybe they changed this with Vista SP3... but if they did, it's just another reason to question why you'd want Windows 7 to begin with, no?
-DrGonzo