I found a fix 4 you. It is not exactly the easiest thing to do but feel free to ask help.
"I finally got this to work - the fix was pretty easy once i stumbled on to it (for me anyway - I hope it works for you)
The offending agent appears to be the Microsoft UAA Bus Driver for High Definition Audio entry under the System Devices category in the Device Manager.
It needs to be uninstalled before installing the realtek drivers. It won't uninstall unless you disable it first though. After disabling, then uninstalling, reboot and install the realtek driver. This was finally successful for me.
I had already removed the KB888111 hotfix during earlier install attempts with no success. I'm not sure if this is required for the above to work but if doing the above doesn't work for you, go to the registry and delete the
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows XP\SP3\KB888111
entry and try again.
I hope this works for you. I went through a frustrating number of install attempts, failures, reboots, damned "Media" hardware found but unable to install, etc., until doing the above. Install was finally successful and sound now works!"
3930K | H100i | RIVF | 16GB DDR3 | GTX 480 | AX750 | 800D | 512GB SSD | 3TB HDD | Xonar DX | W8
