Hi, maybe you need a third-party program to help you remove or mute audio from recorded video. As far as I know, there are some free ways that you may try to remove the audio. For example: you may use YouTube editor (www.youtube/editor) to do it by just uploading files, dragging files to video timeline and just slide the volume slider to mute the sound. Or if you have installed VLC on your computer, you can also use it to mute audio in video.