Look on your task bar, look for the speaker icon that allows you to update system volume. Double click on that, now in the top left on the first menu bar, you'll see "Options". Click on "Options" and then "Properties". Click the "Recording" radio button, select all the boxes there, then click ok. Now, go back to the top menu bar and click "Options" again. Click "Advanced Controls" if there isn't a check by it. If there is, click elsewhere in the window. Now, go to the microphone sound option, and click "Advnaced". You should see a "Microphone +20db Boost" check box.
Hope that works.
Edit: Nexus beat me, lol.
His is visual, mine is "textual", lol.