Since you tried the software, go for the new drivers. I would uninstall the existing SigmaTel drivers, restart the PC and then install the new drivers. When you restart the PC after uninstalling, Windows will probably want to install drivers, do not let it - cancel that function and then install the new Dell drivers.
Dell forum member since 2002
Dell Inspiron 15 - 5577 Laptop
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Roger that. Not sure when I am going to give this a shot though so if anyone else has the sigmatel high definition audio, upgraded to Vista SP2 and can use TeamSpeak or another VOIP without issue....let me know so I know if going down this road is worthwhile.
I just found this thread for a problem I'm still having on my XPS 420. I've just installed the new Sigmatel drivers Dell recommends but I'm still having my audio problems. I, too, associate my audio problems with my Vista SP2 installation.
My recollections are the same as yours - after SP2 installation, I lost visibility to my audio configuration software.
My sound card works with some software (iTunes, Raphsody) but not Spin it Again (audio recording software).