ok here is the way on a NF4 SLI-DR mobo the sound hardware is! 8 channel audio is always on at least the hardware.on the module, all that you need to get running is the right line out and the right front line out jumpered, also same for the left pair. Then make sure that your sound hardware is running, I.E. subs, speakers, make sure that everything is pluged in right, both on the mobo and the equipment.
also you need to make sure that you have the latest sound drivers for the NF4 which is the nvidia 6.70 drivers. I think. then go to your task bar and double click on the NVidia mixer, then go to speaker mode, second tab on the bottom, make sure that you have 7.1 selected or your speakers will not function!