Yay! Microsoft must have listened to all of the users who were complaining that they would not be able to disable Vista’s startup sound. In the latest build, version 5728 that was just released the other day, you’ll find a new option in the Sound Control Panel. There is a checkbox that says “Play Windows Startup Sound”:

Vista Startup sound

So I am content with this solution…kinda. I am very happy that they let me turn off the startup sound but why not give me the option to customize what file gets played just like every other sound setting has? I wouldn’t mind having something a little more subtle but that standard Windows “melody” is just too loud and annoying. A simple beep would serve the purpose quite well.

News Source: Windows Vista Team Blog
Thanks for the tip Marcos!