I have the same Asus motherboard and am having the same problem. I also only have one tab on my manager window unless I disable front audio port detection. Even so, I do not have the option of switching between HD Audio and AC97, as pictured in post #10 of this thread. I have tried all manner of drivers
and unplugging the front panel ports from the mobo and using only the rear ports. None of it has gotten me any sound. I have a usb bluetooth dongle that use to run sound through bluetooth speakers, and that works, but I can't get audio through a headset. Been beating my head against this issue for some time, so I hope we get it figured out here. I'm a gamer, so not being able to run a headset with a mic is major hindrance. I'm considering trying out a usb adapter that I could use to plug my headset into a usb port, but that's a workaround, not a solution, and an unnecessary expense if it doesn't work.