Win7/XP system laptop two speakers one sounds a silent

1. Win7 operating system
In the lower right corner of the taskbar, right click on the small speaker, the following interface appears, click on the playback device;
double-click the speaker; speaker properties, click level, click balance; Adjust left front and right front; after the adjustment is complete, you can test it!
During playback, select the speaker, click on the configuration, the right picture appears, click on the test.

2.XP operating system
lower right corner of the taskbar, double-click the little speaker icon;
some adjustment balance can be adjusted to the middle.