Way to set up auto-mute on XP’s startup?

I’ve got some program or another which keeps turning my annoying default startup, restart, and shutdown -noises on.

I’d like to either set up XP to automatically mute the sound every startup and shutdown, or find a way to prevent the little registry-highjacking/resetting that’s going on. I imagine the former might be easier, but whatever’s simplest.

Thanks.