Q: I install ATI 2xxx, 3xxx, 4xxx series PCIE VGA card on the motherboard. After installing all Windows® XP drivers from the motherboard, it still shows an unknown "audio device on the high definition audio bus." message under device manager. What could I try?(1/12/2009) A: There is an integrated audio chip in the ATI 2xxx, 3xxx, 4xxxx series graphics cards.
Please install ATI HDMI audio driver.
http://ati.amd.com/support/drivers/xp/hdmiaudio-xp.html