My PC keeps muting my microphone. Why?

Periodically after starting my PC I find that my microphone has been muted. I have un-muted it several times, but something checks the mute box again. Is there a way to stop the mic being muted, or to set the default to be un-muted?
Lance, October 2003


done
i tried going to control manager,sound, and had it update drivers.i had some sis1702 or something like that,after it updated i had something else and it seems to work

jto, January 2009
I seem to be getting the same problem...

dave, October 2008
how do I make my microphne work in window live

Jehnny, July 2008
An application you are using may have a default volume level set. This level may be too low. So each time the application starts it changes the volume level to be too low.

Michael Scott, August 2004