Windows 7 volume On Screen Display?

3RVX is a skinnable volume display and controller. It shows your sound volume level with its on-screen display (OSD) and also allows you to control the volume via a skinnable slider or custom hotkeys. Supports drive eject notification, mouse hotkeys, and a wide range of customization options.

Unfortunately, 3VRX doesn't work well with 64-bit Windows. Instead, try a free app called Sound Volume Hotkeys.