This message from dean-dean about re-enabling a disabled microphone just
might help:
---
Right-click the Sound icon in the notification area, and choose Recording
Devices. On the Recording tab of Sound, right-click an empty spot of the
window, and put a checkmark next to "Show Disabled Devices" and "Show
Disconnected Devices".
-----
Use the Playback tab rather than the recording tab, and check both choices.
It enabled me to get my built-in microphone back.
Good luck.

"acruet" wrote:

I attached some remote USB speakers, then when they are removed my laptop
refuses to revert to its built in audio device.
I have re-installed the device drivers but I cannot see the built in Audio
device in my device manager.
There is a bulleting dated May 2007 that says the USB device remains
recognized even if it is physically disconnected.
I need my audio device back. What can I do to be able to use the audio
device again?