Start here, ASUSTeK Computer Inc.-Support-
Work your way through the dropdown to find your motherboard, and get the updated driver
and X-Fi software (if available). If they do'nt have an updated version for your motherboard post back the motherboard model, and we can point you to another board that uses the same sound card and has updated drivers
(Asus is awful for that sort of thing).
Whatever you do don't go to Creative for anything as there is nothing even remotely X-Fi like about that sound card (not even really a sound card, more like a riser card), it is purely a SoundMax/ADI based card that gets to use some of the X-Fi software (X-Fi MB).