How to disable Internal Microphone without disabling external mic?

WynnSmith
WynnSmith Member Posts: 3 New User

I have an Acer Netbook D150-1165.  The internal mic is extremely noisy at all times.  I've plugged in an external microphone.  However, the Recording tab of the Sound Device Manager only reveals one device.  If I disable it, I lose both microphones.  How can I disable the internal mic while keeping the external mic?  Thanks in advance for your help.