1, find the "Control Panel" in the computer and start the program, as shown below.
I use win7 system, and so does xp computer.
2. Find the "Realtek HD Audio Manager" setting option in the control panel, and click it as shown in the figure below.
As shown in the above figure, the position enclosed by the red line is to set the volume of the left and right channels, where L stands for the left channel and R stands for the right channel, and the setting bar in the middle position is as big as the left and right channels.
If you drag the setting lever to the far left, there will be no sound output in the left channel, and if you drag the setting lever to the far right, there will be no sound output in the right channel.