I don't know too much about moding your .inf files. Maybe , try right clicking on the installer, properties, compatibility tab, tick 'run this program in compatibility mode for' then select 'Windows 98' from the drop down menu.
If that doesn't work after that then it maybe time to curse Vista and think about a new sound card - or use onboard sound?
Is this a new build or have you just installed Vista onto a current PC?
if your PC in newer than your s/Card then just run your Onboard sound as that will be better anyway.
if you need good sound then get like a X-fi Xtreme Music or something.
the problem is, that this soundcard is one of the last, that supports a3d 2.0 and i doubt that the X-fi Xtreme has that feature. thats why i want to use my one