It is left hidden, so many users do not know, we gathered this information and presenting for you.please clearly check this.......
1) First go to run ( i.e Press WINDOWS+R) .
2) Type the regedit in that box and press the Enter
3) Go to the HKEY_CURRENT_USER > AppEvents > EventLables.
4) Go to the Windows logon in the Left pane and select it.
5) Now change the DWORD value to 0
6) It just excludes from the CPL key
7) Repeat the same steps for the Windows logoff too.
8) Go to Control Panel by Pressing WINDOWS+X
9) Now go to Hardware and Sounds.
10) Here you can select the sounds and change the system sounds.