As WHS is a server, you really shouldn't be using it as a desktop as well. You are very likely to 'break' something and render the whole system unusable.
Also, as WHS is based on Server 2003, it's probable that the drivers you are trying aren't suitable anyway.
Again though, it is not designed to be accessed from the desktop; all operations should only be done through the Console on a Client, as many of what would be the 'normal' server 2003 tools and operations, interfere or damage the Hone Server portion of the installation, so unless you really know what you are doing, beware of possible problems.
As an aside, playing sound back from the server through the Clients or your Xbox etc., doesn't need and sound card or drivers on the server.
Colin