When someone asks for "Windows Movie Maker" we can't be sure what they are asking for. The last "classic" version of Windows Movie Maker was Windows Movie Maker 6.0 which was created for Windows Vista. Some people have installed that on Windows 7 and perhaps
that is what you are asking about?
Install Windows Movie Maker 6.0 on Windows 7 (or 8, 8.1, 10)
Starting with Windows 7, Microsoft stopped including a version of Movie Maker that was part of Windows and created "Windows Essentials" that included a new version of Movie Maker called "Windows Live Movie Maker". That name persisted until the version in
2012 when they dropped the "Live" branding and returned to calling it Windows Movie Maker. That can be installed on Windows 7, 8, 8.1 or 10 also. It has the newer interface with a hybrid storyboard/project area and not the traditional timeline of the "classic"
version. If that is what you are looking for, this thread has already provided links to install it.
Where
to get a Safe Download of Movie Maker 2012