Volume Mixer in Windows 7, not just show device volume but also lists all applications that are currently running and producing the audio. You can control the audio of any of the application from there on. So when you are having more than one application that is producing sound you can control from here and stop it as well.
Some times when you browse folders in details view, the view may be cluttered and you might want to resize the column widths manually to get the complete details fit in a single screen in the horizontal direction so that you need not use the horizontal scroll bar to view the details which are off screen. Alternatively, Windows Xp provides an automatic way to adjust column width. Just select any row in the list and press they key combination, “ctrl + ‘+’of the numeric key pad”.