I have Windows Movie Maker on my laptop, it's 6.0 for Vista, and i make videos (AMVs, etc.) for my youtube account and i just finished one recently and my movie maker won't publish videos! every time i set it up and hit "Finish" after i select what kind of video i want it to be (.Avi, .Wmv, etc.) it crashes.

Does anyone have any idea on how to fix this? i really need help please!
I can't downgrade, i tried using it on another computer that had an older version and it said the project file wasn't supported by the older version.

The only thing I can think of is to uninstall it then reinstall it. Make sure you do a reboot in the middle though. Sometimes other applications can conflict, if you have your restore CD's that came with the laptop you could try re imaging it, but you will lose all your stuff if you do that so be careful.
I am betting though if you are trying to do that, you probably have other video processing apps installed. Maybe there is a conflict there.
If it comes standard with VIsta, you may find that you cant uninstall it. In that case look in add remove programs and look under windows components. You may have a repair option there. But this usually doesn't work too well but it is worth a try.
Good luck