Microsoft UAA driver, which is included with Microsoft Vista, supports the HD Audio Device on graphics cards. No additional HDMI Audio Driver is required to enable sound with Microsoft VISTA operating system.
If your motherboard has a Digital Output Device (SPDIF), VISTA recognizes this device as the default digital output device. You need to change the default device to HDMI. To do so, please follow the steps below:
1. Open "Control Panel" and double click on "Sound"
2. On "Playback" tab right click on "Digital Output Device (HDMI)" with the TV icon
3. Select "Set as Default Device"
4. Right click on "Digital Output Device (HDMI)" with the TV icon again and click on "Test"
5. You should hear sound from left and right speaker of your TV set
6. Click on "OK"
<p>Okay...but what about XP?</p>