question regarding sound/microphone

Hi everybody,

not a major issue but...

I have a microphone connected to the back of my new PC (Vista Ultimate),
which I use with Skype.

Strangely enough, I cannot switch off this microphone. If I move it around I
can hear the sound in my speakers.

I have been to Control panel/sounds/recording, then selected the microphone
in question, Properties, Recording level tag, clicked on the button next to
the "potentiometer", but it didn't change anything.

In short, I went everywhere to try to find a control for this mike, to no
avail.

is there a "secret" command somewhere? Any clue Anyone?

(in XP double clicking on the Speaker icon on the right of the taskbar
opened a volume control panel that included the microphone control and
vu-meter. With Vista one can only open a small window which, in my case, has
3 controls : Speakers - Windows sounds - Skype. The button associated with
Skype has no effect either)

Many thks in adavnce for your kind help.

With brgds,
Daniel