You are asking something that is well discussed and as such I won't give any of the common answers as you would have done that already.
When all attempts to record fail and all the prior suggestions fail I whip out an audio cable to connect the headphone out to the microphone or aux input. This works for the odd machine that nothing else worked.
Hi, everyone. For several years, I had been using Audacity occasionally to record the output of my computer's speakers, using the "Stereo Mix" input option (recording directly from the Realtek audio controller). I have used it in the past to record streaming internet radio (for example while I'm away but want to listen to a particular show later on without downloading the podcast) and to record business calls on Skype for future reference.
When I got a new laptop several months ago (still Windows 7), I found that any time I tried to record using the "Stereo Mix" option, I wound up with nothing. Pure silence. Flat line.
I checked the input options a few times, then went into my computer's control panel to make sure there was no issue with sampling rates or anything else. Everything is fine, and it should be recording the audio just fine. But it isn't. Still nothing.