Yeah, that's my fault. I assumed registry keys were a standard for every WLM user, but it appears that it's location dependant. Now, this may mean that there are some keys that I don't have, which Mute will not mute, but I doubt it.
Adding that key won't be necessary. I've fixed the script to ignore keys that you don't have. Check
the first post for a newer version.
And to all of you complaining that Mute removed your sounds forever, I'm sorry, but it really isn't that hard to unmute them. Check
the first post for instructions.