Reinstallation dvd windows vista home premium 32 bit?

I had reinstalled it once back there a couple of weeks ago and at the time i didn't know it needed a product key to fully unlock it. I have tried reinstalling it again but the install windows box doesn't come up, what would be the problem? http://www.flickr.com/photos/freeed/363935596/in/s... that box in the screen doesn't come up