I've noticed an oddity in my device manager for a long time now, probably a couple years at least.  There are two entries for "Microsoft UAA Bus Driver for High Definition Audio."  I get an exclaimation mark in my device manager next to one of them.  The properties page for this one says that there are not enough resources for it.  I am not convinced it is a duplicate installation... I've tried removing it and rebooting, think I've even tried removing both of them and rebooting.  It just comes back.  The only symptom of a problem I see is that I can't run the sound test from the audio software in the tray app.  Not really a big deal, but if anyone else has come across this I'd like to hear if you've fixed it.

Looks like Microsoft has a hotfix related to this device, but I can't find any info to indicate that it's related to fixing my problem or not. not sure if I want to try it or not since I don't know If I can roll back to the old driver if it doesn't work or worse.   http://support.microsoft.com/kb/888111

I know this is an old thread, but I was dong some troubleshooting on my HP DEC recently and came across this UAA bus driver and thought I would share: http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareDescription.jsp?swItem=ob-45958-1&lang=en&cc=us&mode=3&

I also have a duplicate high definition audio driver entry in the hardware manager.  Mine shows with an exclamation mark beside it and the details say that the resources required are already in use and to disable the other one.  I'm wondering if it's due to the audio hardware for the HDMI interface on the my ATI radeon 4350 card.  I have my TV hooked up using a dumb DVI to HDMI converter cable so I'm not getting audio over the DVI connector.

Neil.