Or you could get the
Ultimate Boot CD for Windows
Will give you a windows explorer like shell and a lot of the same utilities as the dos ubcd, including password recovery.
I've used this disc to rescue many computers, not only from lost passwords, but from viruses and spyware as well.
Edit: I haven't actually used this on a Vista machine yet, since the only Vista machine I have is my laptop. And it hasn't needed rescuing yet. All the systems I've rescued were XP machines. But I would think it should work with Vista too.