I don't think you could have possibly been burning a DVD with the Windows wizard, it only allows for CD burning. Plus, burning an AVI file to disk is not going to be readable in a DVD player, even if it were burnt to a DVD and not a CD. It's a different kind of file that's nessecary.
I trust these are home videos or non-copyrighted material you're trying to burn and not commercial blockbusters?
Edit: I've just read your other post. Please don't double post in other sections. One thread: one problem.