It is easy to extract audio from a video. Try DVDFab Toolkit which is free on Windows to edit video. After launching it, click the button of “Extract Audio” under “Audio Tools”. Load your video and set the options of Track, Output, Audio Codec, Sample Rate, Channels and Bit Rate. Then choose an output folder and click the button of “Start”. This is how to edit a video with DVDFab Toolkit. It is very easy and fast.
i  Windows