One of the questions I get asked most often about Longhorn is in regards to audio hardware.  1) What is a card that works under Longhorn, and 2) How do I get the drivers working?

My only example is the Creative Sound Blaster Audigy 2, (Adam Hill reports that his SoundFusion GX270 functions as well.) a very common card, with varying options, including the platinum version with a drive bay with inputs (but I digress...). Strictly disabling an onboard soundcard is not enough for Longhorn to see the PCI slot card as primary.  On my system, running a dual-boot of Longhorn and XP, XP saw the correctly disabled onboard card, and enabled Audigy2 card as primary. Longhorn decided to try to use the disabled card, resulting in a very soft high-pitch sound out the spk-out jack of the Audigy, and no sound out the onboard card.

To fix this, simply install the drivers by running setup off of the “Installation and Applications CD, ” but in compatability mode. To do this,

1. right-click the setup.exe on the cd's root, and copy it.

2. right-click on your desktop and paste a shortcut to the exe.

3. right-click the shortcut, and go to properties. 

4. click “Other Properties” on the left pane, and choose compatibility from the list.

5. Check “Run this program in compatibility mode for:” and choose “Windows XP.”

6. Run the shortcut, go through the install process and reboot (or just restart explorer.exe from task manager; it doesn't really require a reboot, although I bluescreened inbetween).

Audio should be working just fine!