If you have one movie or video spread across several files, it can be annoying and confusing. Merging the multiple MP4 files into one continuous movie makes it easier to watch and organize on your computer. Merging video files is easy with Windows Live Movie Maker, making it possible to watch your previously cut-up media file as one long, continuous movie.
Launch Windows Live Movie Maker. This free program comes included with most versions of Windows.
Click on "Add videos and photos." Select the video you want to play first and click "Open." Repeat this step for each video you want merged together.
Click on the blue button in the top-left corner of the program window. Go to "Save Movie" choose a video quality format. Click "Save" to save the file. The saved file will have each MP4 file, merged together into one continuous video.
Your merged file will be a WMV file. Use a third-party program or online conversion service (see Resources) if you want to convert it back to an MP4.