1. Check that it's plugged into the correct hole. The hole should be pink in colour.
2. Start > Control Panel > Sounds and Audio Devices
[*]Select the Audio tab. Under Sound Playback, take note of the sound device you are using.
[*]Click on the Voice tab. Make sure that under Voice Playback and Voice Recording, the devices used are the same as the one you seen in Audio tab. If it's not, changed them accordingly.
[*]Click on Test Hardware to make sure that it's working properly.
3. Start > All Programs > Accessories > Entertainment > Volume Control
[*]Click on Options > Properties.
[*]For Mixer Device, choose the device you've done for Step 2.
[*]Under Adjust Volume For, select Recording.
[*]Click OK.
[*]Look at the Microphone column. Make sure that the slider is dragged up high enough.