The drivers (eg. AGP, VGA, USB,...) from the VIA drivers-cd can only be installed when you have installed Service Pack 1 for WinXP before.
Please install Windows Hotfix KB892050
Deactivate ACPI in the BIOS.
Please use this driver : http://www.viaarena.com/default.aspx?PageID=420&OSID=1&CatID=1010&SubCatID=105
Check in settings that all channels, like Line-In, are activated and not set to 0.
In Vinyl Deck select Multichannel (4 channels or 6 channels), then select Smart 5.1.
In system control panel, Sound and audio devices go on Audio-tab, volume of sound output, options, properties.
Select "Others", then Multi Channel and confirm. Now you have volume control on all speakers (Front, Rear, Center, Subwoofer). Activate output on all channels and you should hear sound from all speakers.