When I got my inspiron, I never really knew the function of the far left button on the media panel of buttons and since I couldn't get it to work, I didn't worry about it. After seeing some friends with a functioning mute button, and I am in a position where quickly muting my system will greatly come in handy, I'd really like to have it in working condition, but I can't get that button to even light up when I push it. Is this a quick fix, or do I need to send it all the way back to Dell to get this function?

Yes, notebook still under still under warranty.