no sound from x-fi?

[Maverick986]

didn't know if this should be in gen. software or here but any way heres my problem...i installed an x-fi extreme audio/music..can't remember which exactly about three weeks ago and have had no problems with sound..went and reinstalled windows media center and now i can't get the thing to put out sound...i've tried to install the drivers off the cd and dling them but every time it goes and installs them it gets to a certain point and either restarts as the case w/ the cd or just locks up as with the dl driver...i've run windows update and it comes up with a dl for the card and after i dl that it shows up in sound/audio devices but still no sound..the only sound i get out of it is when i didn't dl the windows update it had a hissing noise...any ideas as to what is going on or what to do?