Step 1:Free download Download Ultra Quicktime Converter
Step 2 : Launch it and get ready to convert M4V to MP4.

Step 2: Click
to Add M4V files.

Step 3: Click Output Option, choose MP4 Format (*.mpg), ofcourse you can set the output folder, quality and other settings while convert m4v to MP4 file. (note, you can also use it to convert m4v to MP4 4 (mp4 format))
.
Step 4: Click
to Start Convert M4V.

OK, We have finished the whole conversion of M4V to MP4, Apart from convert M4V to MP4, you can also use it to Convert M4V to other video files, such AVI, WMV, MPG and so on. Just Free download and enjoy it.