I go to Sound setting in the control panel. I check the audio tab. I check in volume there is nothing to unmute. I check in OPtions -> properties -> Record only options are Line In, Rear, Mic and that is it. THere is no option for Stereo mix. If it help to fix the problem the computer I have is a Dell. I have a feeling they disable it completely. I do not know how to get it back.