Assuming that you're referring to Movie Maker 2 as a component of Windows XP, it can't be completely uninstalled.  See the information at the link below for details.

http://www.eicsoftware.com/pictures/PapaJohn/Website-MM2/MM2-Removing.html

Sorry, but in the course of events I need to install it again, how can I ?

Go to http://www.windowsmoviemakers.net/forums/ and search for uninstall /Reinstall .

I can't get Movie Maker to work with my Dazzle DVC80 =(