JoeAirPort,

Check in your BIOS to disable the on-board sound. I don't know what motherboards or chipsets your manufacturer is using, but its usually Del, F10 or ESC at system startup to get into the BIOS. Looking in all categories, but it will probably be found in peripherals. You may see something like AC97 - Enabled.

If you look in your motherboard manual, it should point you in the right direction. If you are still having problems, let me know your system model and I can run down some additional info.