Mute sound from other users in Windows 7

I use MonitorES (http://code.google.com/p/monitores/) here at work to mute the sound whenever I lock my system. I assume it would work similarly over fast user switching but I've not tested it. It's worth a shot. It's a standalone executable that sits in the taskbar and it's free.

I know there's an option to stop media players from playing and also to mute but if it's a game it may not mute it. In Windows 7 I believe there are application based sound preferences so you could mute the browser's sound but then it would also be muted for you. If you're the one doing the switching, you could always mute his game before the switch. (Not ideal I know). But that's Microsoft's official position on it: "To resolve this behavior, either upgrade the programs, if applicable, or stop the sound-emitting program before switching users." from support.microsoft.com/kb/301681

I had the same frustration and decided to scratch this particular itch. The result is Sound Killer - http://jugglingcats.github.io/soundkiller. Enjoy.