Vista - Movie Maker Cannot Save or Move Project to DVD

Am using Vista Home Premium.
From the onset, Movie Maker never worked properly at saving projects. Even
if I create a new "test" project with only one JPG in it, I cannot save that
project.

Neither File > Save Project nor File > Save Project As displays the expected
dialog box. Clicking the Close button gives a prompt to save, but it also
fails to display a Save dialog.

Futhermore, when I click the Publish to DVD link, the project cannot be
moved to the DVD Maker--probably in part because it's impossible to save a
project.

It tried to run the reinstall or repair programs (Control Panel > Programs
and Features), but Movie Maker does not appear on the list! :-(

How may I reinstall Vista's Movie Maker, please? I thought that I would try
that before trying other approaches.

Thank you