Wave Turns Mute..

Hi All,
I am facing a big problem in my Win. XP, When ever i try 
to change the volume settings through media players the 
wave turns mute there by reducing the volume entirely. I 
have tried out updating drivers but of no luck. Even with 
other media players the same is the problem.
Has anyone faced the same problem & if u r sucessuful in 
finding the solution please let me know.

Thanks for reading my post.

Sandeep