Turn Off Windows Sounds : Windows Registry Tricks

Windows sounds or beeps are often annoying and can be turned off without turning off the other sounds. This can be achieved by a simple registry trick.
Open the Registry Editor.
Navigate to HKEY_CURRENT_USER\Control Panel\Sound.
Click on Beep and set the value data to " No". 
Exit the Registry Editor.

User Accounts Control without blocking the desktop background in Windows 7

If a UAC window occurs, the operating system blurs the rest of the screen making it impossible to read important information.
To start the registry editor, write 'regedit' in the search field. Right click on regedit.exe and click on 'Run As Administrator'.
Navigate the tree structure in the following order.'HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System.'
On the right hand side of the window,click on 'PromptOnSecureDesktop'. Double-click it and set the value
to 0. Confirm with OK and close the registry editor. The changes take place without rebooting the
system.