My computer case has a plug that has an HD audio connector and an AC'97 connector. It depends on what motherboard you have, e.g. if your mobo has HD audio support like mine does, plug in the HD audio connector and leave the AC'97 unplugged. If you have an older mobo that doesn't have HD audio on it, plug in the AC'97.
My computer case has only one set of cables but they are not bundled up, every single one is separate cable and I don't know which cable goes to which pin and that is my question, where to connect each one of them not whether i have hd or ac97.