The answers to this type of question are all old. Even the most recent queries (2016) have ridiculously ineffective, unhelpful responses from alleged Windows/Microsoft peeps.   I have Windows 10, the latest version of Movie Maker, and my laptop has been completely cleaned and updated recently (read: NO BUGS/VIRUSES).  I purchased a new Canon Vixia camcorder LAST WEEK and used it to record reunion events, using the MP4 format to make it easier to share the files (than HD movies). I transferred the videos via SD card onto my laptop into Windows Media Player, and they are saved in my Pictures files.  Each file plays perfectly in Media Player and as a file in "Picture".  But when I imported the videos into Windows Live Movie Maker (again, I have Windows 10--ugh), I get NO AUDIO.  These are "approved" file types for WMMaker.  I don't want an answer that gives me a bunch of questions. I want a SOLUTION to this problem that is obviously a WINDOWS issue, since hundreds of people have complained about it for years.  What's the deal, and why hasn't this "bug" been fixed in Windows 10?  Bottom line, am I going to have to purchase a "real" movie-making software program just because Windows can't get its act together? (Read: yes, I'm angry.  I made movies using ancient versions of movie maker years ago with zero problems, and it was much easier than the WMMaker version in Windows now.)  Oh, and don't tell me to check my audio volume levels/speakers.  Already done, repeatedly, for both the WMM and my laptop speakers/volume.  [I'm really a nice person; but seeing hundreds of people ask the same or similar questions for years and find little or no help from Windows to fix this problem of no audio after transferring videos into WMMaker, I get irritable and meannastyugly.]