shiraz_kaka :
HOw to enable 7.1 on my Realtek ALC888.. connected all three wires to the analogue out put behind the pc .. but only 5.1 works although the intel site says its 8 channel audio 5.1 + 2
You connected all "3" wires? If you were hooking up a 7.1 speaker setup you would be using more than that. 7.1 setup you need (1) Center/Subwoofer, (2) Rear left/right (3) Side left/right (4) Front Left/Right.
In the Realtek HD Audio Manager under the Audio I/O tab select 5.1 and it will show you which 3 plugs you need to plug your speakers into in the back of the computer. Should be the orange, black, and green.