If you haven't already solved this problem, I had a similar thing with my Gamesurround Fortissimo II card. I've just got it working by first installing the vista/xp drivers from the hercules website. Then I went in to device manager (right click computer->manage) and found the sound card (it may have been called unknown device), right clicked on that and chose update drivers and then pointed the wizard to the folder :
C:\Program Files\Hercules\Audio\Crystal Sound cards
It successfully installed the drivers and now I have sound.