Even the latest version of Microsoft Video Maker supports the previously used MSWMM format and thus can import these files and work with it. Using the File ► Save movie function is then possible to export the projects as MP4.
Convert Microsoft Windows Movie Maker project to MPEG-4 video file format.
We found 2 software records in the database related to .mswmm to .mp4 file format conversion.
Microsoft Windows software - convert mswmm to mp4 on Windows
A video editing software distributed with Microsoft Windows
Convert from mswmm file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned mswmm to mp4. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A proprietary video editor for Microsoft Windows