Have you found, your volume icon on taskbar dissapear. May be you have checked and try to do what you can do, but still the icon dissappear, and it could you have try open taskbar properties, and found volume icon became grey color, it’s means volume cannot checked.

Then all you need is to delete the iconstreams key registry under registry windows using regedit. Be carefull to do that, here is the link how to do that:

http://answers.yahoo.com/question/index?qid=20080521125108AAnBI8c