The sound card isn't disabled, there are now jumpers and it is enabled in the BIOS. The only issue is that it does not "detect" speakers or headphones being plugged into ANY jack. With these Realtek audio chips the seem to need to detect a output device in order to acutally output sound.
I've git the same issue here. I swapped motherboards without installing windows (motherboards are nearly indentical, same chipset, same soundcard (ALC888 HD Audio) etc. just different manufacturer).
Have you found a solution yet? I'm not really willing to reinstall windows and all my programs, so if no solution is found, i think i will just buy a pci-soundcard.