1.Click ‘Begin’ – ‘Setting’-‘Control Panel’, double click the icon of ‘Sound and Audio device’(it is a loudhailer, WindowsXP users betake‘Classic View’), open ‘Master Volume’ window, find out ‘MicroPhone’/ ‘SW Synth’/ ‘3D Depth’ columns. Then Select each ‘Silence’ option of them, make the voice of MicroPhone sent to the other’s computer not make from the sound card directly. Finishing the setting is like this,

(Notes: The setting is very important to eliminate call echo! But different Operating System use different sound card, so the Control window that you see may have some changes, maybe ‘Silence’ option have been selected. Such as in WindowsXP, Master Volume window of Loudhailer System and MicroPhone Record Voice are separate, whether or no, you must select each ‘Silence’ options of ‘MicroPhone’/ ‘SW Synth’/ ‘3D Depth’！)
* If there is no ‘SW Synth’/ ‘3D Depth’ columns in the sound card, you only need to select ‘Silence’ option of ‘MicroPhone’.

2.Click‘Attribute’of‘Option’menu in the‘Master Volume’ window, select ‘Record’ in the‘Attribute’window, make sure that ‘MicroPhone’option have been selected ,click‘Confirm’button. So the‘Master Record’ window will be show, find out ‘MicroPhone’column, select‘Select’option, make the MicroPhone be currently record object and the volume be appropriate（don’t too high!）.As follow picture,

Summary
You maybe can’t see the same setting windows of above picture from your computer , but you must select each‘Select’option below ‘MicroPhone’/ ‘SW Synth’/ ‘3D Depth’. You should adjust each button 75% location in the ‘Master Volume’ window, and adjust each button 50%(locate midst) location in the ‘Master Record’ , this is the perfect setting for most computers. To specific computer setting is different, you need to adjust above buttons properly until to get the best call effect. Of course, your microphone and earphone or USB phone usually have volume regulate button, to adjust it well will improve call effect.