You must be in the Time-line mode of WMM
> Click the + button beside the word Video on the video track
> Right-click the Audio track of this menu
> Click Mute from the menu
Example (Click to enlarge view)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhu2wEDkXoq7kjSPc5Tty77QW6cy-qUUsiADIRMcFknN0l4LB8cuI78s1CTxMJmWyHpV0FH_YCt6dz1xxSj-pJBugj-qtVQhJyowO3PFv0GV4tbD1WloGL1oNfyRl6GQKB3-r6XlryETHQ/s200/Mute+Video+Audio.png)
Voila! No more audio on the video! You can also use this menu to lower the video volume level, fade the audio in/out, etc. Just remember, the + sign beside the word Video in the Time-line view opens up the menu options specifically for the video in your project.