If your keyboard lacks of volume controllers or if you like to execute actions in Windows with the least amount of effort, then the FREE Volumouse utility that allows to control the computer’s sound with the wheel of the mouse is just what you may be looking for.
Volumouse has a variety of customization options, you can configure specific rules that must be met before you can use of the mouse’s wheel to control the PC’s sound (e.g., Ctrl key or the left mouse button should be pressed), making it possible to continue using the mouse normally. You set up a total of 12 different rules in 2 pages giving you a wide variety of scenarios of how to control the computer’s sound.
Volumouse has been out for a while, but now there is a new Volumouse 2 Beta 1 that adds support for x64 systems, in other words you can use this free utility with Windows 32 or 64 bit, also add some fixes and it runs in Windows Vista, Windows 7, and Windows Server 2008.
So if you are serious about controlling the computer sound Volumouse 2 makes it a kids game. You can download and find more details at NirSoft page.