First: It is possible that the speaker and microphone are close to each other, so that they can make their words from the other speaker voice through the other side of the microphone passed through, resulting in an echo. The method is to let the other person use the headset chat or microphone away from the speaker.
Second:
Windows XP Setup Method
1. Open "voice, voice and audio Devices" in Control Panel, open advanced audio settings on the left;(double-click the small horn in the taskbar to directly enter the volume property)
2. Click Options to open Properties. In the Select the following Volume Settings dialog box, select Microphone to click OK to exit.
3. Return to the volume control interface to find the microphone to put the following "mute" on the check mark.
Ii. Windows 7 Setup method
1. Open the sound in the Control Panel, click on the recording or directly right-click the small speaker in the taskbar to select the recording device;
2. Right-click "Microphone" to select Properties;
3. Select "Listen" To remove the small hook in front of the listening, to determine the preservation;
4. Select "Enhance" to hit "Echo elimination" Before the small tick, to determine the save.