Hello Student62,
Welcome to Microsoft Community Forum. I understand that you want to remove/mute the audio within your recorded video. I will assist you on your inquiry.
You can mute the video's audio by following the steps below:
- Open your Movie Maker and the video file.
- Go to Edit tab
- You'll find Video volume on the upper left part of the screen. Click on it and adjut the slider to the left to mute the audio sound of the video.
- Add your audio narration and click the green line on the preview pane.
- Click the Music tools on the upper side of the screen
- On the upper left part of the screen, you'll find Music volume. Click on it and adjust the slider to the right to make the audio louder.
Let us know the results afterwards.
Thank you.