As it is a portable version, you need not install it. Download the zip file and unzip in a folder. Run the ‘Runonce.bat’ file preferably as administrator. Then launch movie maker by clicking ‘Moviemk.exe’ file.
However, while testing this with Windows 7 build 7000, it shows some errors. For example the preview window remains black when previewing a movie. The developer should look in to that. [Via].