Volume Control Indication

Hi. First post, long time lurker.

Anyhow, I built a system a few months back and all seemed to be going well. I have the Dell 24" LCD and a Logitech Gaming G-15 keyboard. The keyboard has some multi-media keys and a volume control knob and a mute button. All of those keys work. However, when using the volume control knob or the mute, the monitor USED to display information on the volume, such that a greenish indicator would come up to show the volume level or tell you that MUTE is on/off. I seem to have lost that function, but the keys work fine (i.e., the volume changes or the system goes MUTE). Strangely, the keyboard has an LCD that used to bring up a slide indicator on volume as well. That no longer functions. So, whatever file the monitor would access, I'm assuming the keyboard LCD screen also accessed.

I think I have a corrupted DLL file, but I don't know which one. Anyone have a clue?

Thanks so much for any help.