Windows Vista start up sound sometimes a bit annoying. If you’ve decided that you don’t want to hear that annoying sound again..ever, here’s how to do it.
- Click the Start button and then type “sound” (without quotes) in the search box.
- You’ll see a list from the search result, choose “Change system sounds”, the Sound window dialog boz will then pop-up
- Uncheck “Play Windows Startup sound” option
- Don’t forget to click OK if your finished

From now on you won’t hear Windows Vista start up sound.