Volume control in task bar missing XP Pro

Hello all, I have XP Pro SP2. Volume control Icon disappeared in my Task Bar. I opened the Control Panel and Checked: Place volume icon in taskbar." But then I got an error message that said "Windows cannot display the volume control on the taskbar because the Volume Control Program has not been installed. To install it, use Add/Remove programs in control panel." I installed everything and no luck.
I searched threads for similar problems here and so far I have been unable to fix my specific problem.
Any help greatly appreciated.

 

thanks for your help.