Mute The System Sound on windows 7 [ trick ]

2. Mute The system Sound

I don't know about you, but the little beeps, blurps, and whoops that some Windows programs make are like fingernails on a chalkboard. Do you really need to hear a sound every time someone one of your friends tweets something?
If you want to keep those sounds around but tone them down, use the Volume Mixer. Right-click the speaker icon next to the clock to open the menu shown here. Click Open Volume Mixer to display a set of sliders, with a master volume control on the left and individual sliders for every open program.
Move the slider down for any program you want to soften. Windows remembers your choice and keeps that program's sound at your preset level until you change it.

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