The audio from the Realtek sound card is not output to all the speakers.

Follow this procedure to change the speaker setup for the Realtek sound card.

1. Click the Start button, and then click Control Panel .
2. In the Control Panel window, under Pick a category , double-click the Sound, Speech and Audio Devices icon.
3. In the Sound, Speech and Audio Devices window, under of Pick a Control Panel icon , click Sound Effects Manager .
4. In the Realtek window, click the Speaker Configuration button.
5. On the speaker configuration screen, click the speaker selection down arrow [FIG. 1] , then click to select the desired speaker setup.