When playing video within a product either from CD, network location or local hard disk the video appears to play correctly but without sound.
An update for Flash Player has compromised the ability of the Flash Player plugin to properly render the audio channel of .flv format content.
All delivery mechanisms of .flv (Flash video) content. This includes other sources of rich media content e.g. YouTube.
You should uninstall Flash Player from the affected computer(s) and re-install the latest version.
Adobe recommend the use of the uninstaller from their website to ensure that all components correctly unregister (due to recent 'enhancements' to Flash Player):
1. Uninstall Flash Player:
2. Install latest Flash Player:
Note: To successfully uninstall, any application that may be running Flash content (instant messaging, web browsers, email etc.) needs to be closed first.