If your microphone on your headset isn't working, try the following...
1. Plug in the headset.
2. Go to "Control Panel".
3. Click on "Sound".
4. Click the "Recording" tab.
5. Click on the device you are trying to fix.
6. Now right click that device and set it as "Default".
7. Click "Apply" and then "OK".
You should now be able to use the headset to hear and the laptop microphone to record.