Microphone not working even though speakers are

I just recently upgraded to Win 7 Ultimate and I found that I was having multiple problems with the sound. I have solved the problem with my speakers/headphones after upgrading drivers (et al.), but my microphone is not being recognized. When I go to the Speaker Icon in the system tray and right-click to bring up the dialog then go to recording devices, what I get is this: No audio devices are installed. The playback dialog shows the correct information: High definition audio device. Default device.

What am I doing wrong and how can I correct it?

i'm having the same problem , let me know if you can fix it