SoundMax Digital Sound Not activated

I have a dell Dimension 8400 with a soundmax AC3 integrated sound card. I remember when I first had the system there was a way to change the sound from Stereo, to Digital to analog etc. I since reinstalled the software to clean the system up etc. I have the latest driver and the digital output does not seem to work.

Is there some way to tell if this works? I have a THX certified sound system connected (all purchashed from Dell with the system). It's frustring to me and I don't know how to resolve this. I see AC3 drivers out there that give you significantly more control then the driver that I have from dell.

Anythoughts on how to fix this? I have tried uninstalling the Dell drivers, deleting the sound card in hardward profiles etc. The problem is it just keeps reloading the same driver. Is there no way to get the rig to fire up without loading the default driver? That way I could try different drivers.

Confused and Frustrated at the moment. Any help would be appreciated.