Sometimes it might be necessary to switch off the windows start up and shut down sound when you work in quiet environments like libraries. Some people might also want to change their sound during start up according to their taste. It is very easy to do them both.
Go to control panel (start > settings > control Panel).
Then open the sounds and audio devices.
Go to the sounds tab and then here you will be able to find program events at the bottom. Scroll until you find start windows. Now high light it and then at the bottom of the dialog box you will be able to find the sounds drop down box. Just select none from it. Similarly do it for windows logon windows logoff etc.
If you want you can change the sounds by clicking on the browse button.
If you do not want any sounds at all, then you can select “No sounds” in the sound scheme drop down list.