Green volume bar is not showing in screen

 Anonymous User -
I recently lost my green bar that tells me what my volume control is. It just suddenly disappeared. I can still turn my volume up and down but I cannot see what I am doing as far as how high or low it goes til I hear it. Can anyone tell me how to get my green volume bar back! I have the volume icon in the taskbar it is not missing, Any help will greatly be appreciated.