You cannot control the volume in Media Center when you output digital audio to an external receiver or to speakers on a Windows Vista-based or Windows XP-based Media Center computer

On a computer that is running Windows Media Center, you may be using any of the following configurations to output digital audio from your computer to external speakers:

• An AV receiver or TV that is connected to the computer by the Sony/Philips Digital Interface (S/PDIF) input.
• An AV receiver or TV that is connected to the computer by the High-Definition Multimedia Interface (HDMI)
• A set of digital speakers

In this scenario, you cannot control volume levels to the external devices by using the volume controls in the Media Center user interface (UI). For example, when you press the MUTE button on the remote, the volume does not mute. When you press the volume control buttons that have the plus sign and the minus sign, the volume remains the same. Although the mute UI displays on the screen, the volume does not adjust.

This issue occurs because Windows Media Center cannot control the volume for digital output. This issue affects all digital audio formats. These include the following:

• Digital audio from a video source. For example, Advanced Television Systems Committee (ATSC) and Terrestrial Digital Broadcasting Services (DVB-T) are digital.
• Any alternative digital audio source, such as such as DVDs, CDs, .wma files, and .mp3 files.

To work around this issue, use the volume controls for the audio device that is connected to the Media Center computer. For example, if your Media Center computer is connected to an AV receiver, use the remote or volume control for the AV receiver to raise and lower the volume when playing multimedia content that outputs digital audio.

You can use Media Center to control the volume of non-digital (analog) audio, even over S/PDIF. Therefore, your Media Center Edition audio setting will affect the volume on the AV receiver or on the digital speakers for analog audio. All TV broadcasts that are routed through National Television System Committee (NTSC) or Phase Alternating Line (PAL) TV tuner cards will have analog audio.

Media Center Technical Support

Because Microsoft Windows XP Media Center Edition was included with your hardware device or system, the hardware manufacturer provides technical support and assistance for this software. Your manufacturer may have customized the installation with unique components such as specific device drivers and optional settings to maximize the performance of that manufacturer's hardware. If you require technical help with Windows XP Media Center Edition, contact your manufacturer directly because the manufacturer is best qualified to support the software that the manufacturer has installed on the hardware.

You can also visit the Windows XP Media Center Edition product information Web site at the following Microsoft Web site: http://www.microsoft.com/windowsxp/mediacenter/ (http://www.microsoft.com/windowsxp/mediacenter/)
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.