I'm in Vista and have the sound properties within Vista set to 7 channels with the 2 rear channels disabled but, side channels active. I then went into the C-Media drivers and set the input to 6 channels and output to 6 channels along with either Dolby Digital Live or DTS.
Now the issue im having is that my reciever will reconize that all channels are being sent only when I use WMP11 compared to MPC. With MPC I there is just left and right, nothing else. I've gone to the extent of changing the output within MPC but, the best I can do is get it to use any of the simulated DSP's like Neo:6 or ProLogic2. This still doesn't help me since it's not truly 6 channels.
I don't want to use WMP11 because it allows the videocard to decode the video which causes tearing.
First, I'm assuming that by
First, I'm assuming that by MPC you mean Media Player Classic?
If WMP11 is passing surround sound to the Inferno fine in your current configuration, I think the problem is likely with MPC's settings. I'm not very familiar with that program, or which audio settings are available.
If you can find the settings you need, you might try a different player entirely, like VLC.