You didn't offer much information. So for now, I'd recommend that you check to see if your microphone application is "muted". Left click on your speaker icon. A volume bar will pop up, and at the bottom, you will see "MIXER". Click on "MIXER". You will then see the speaker, mike, and perhaps something else there. There are slider bars there to raise or lower the volume of different sound applications. Also, at the bottom, you will see a small icon. If you click on that it will either mute or un-mute the device that you want to control.