After repairing my Windows XP Prof SP3 installation, I had an issue with my sound. There was no volume icon in the taskbar & I couldn't install Microsoft UAA and I found out none of HD audio/modem devices where recognized even after installation of the correct drivers from the motherboard manufacturer because of the wrong UAA.
This fix from http://www.boredsysadmin.com/2008/03/windows-xp-sp3-and-microsoft-hd-audio.html solved my issue.
If updating the UAA doesn't fix your issue, you may want to try this fix http://forums.lenovo.com/t5/T61-and-prior-T-series-ThinkPad/No-audio-device/m-p/15874#M5711. It was instructed below.
1. Chek if PnP SW Enumerator is installed on your machine (Device Manager -> System devices) - should be listed there!
2. If it is not there then we will probably solve it!
3. Locate machine.inf on your OS, copy it your Desktop and modify it (find ExcludeFromSelect=* and remove the line or simply exclude it from processing by adding a ; at the beginning).
4. Still with machine.inf open, search for SWENUM and check the location of SWENUM, mine reads like this SWENUM.CoInstallers.CopyFiles = 11 ; %windir%\System32
5. Find swenum.sys file on your XP installation CD (mine was in DRIVER.CAB) and copy it to the proper location (I am not sure if it is necessary but worked for me)
6. Go to Control Panel -> Add/Remove Hardware and follow the wizard towards manual selection of device to be added
7. Select Add System device
8. Select Have disk
9. Navigate where the saved machine.inf located (as per Step 3, it was sasved in your Desktop).
10. From the list select standard deviecs (in the left list) and Plug and Play Software Enumerator in the right list
11. Finish the installation
If it still does not work reinstall the audio adapters' drivers. It should work now.