Programs enabling conversion of the file:
If your objective is to convert the file from DVR-MS to the file MP4, you can use any of the applications listed. DVR-MS to MP4 conversion process in every program intended for this purpose (so-called converters) is very intuitive and everyone is able to manage converting a file.
However, bear in mind that the list may also include programs to support and work with the indicated extensions DVR-MS and MP4 - and not only converters. In such a case, you need to open the source file DVR-MS and from the options available in the program, choose ”Save as... MP4" or "Export to MP4".