I talked to my Dell Tech Team about an idea that I had to overcome the omitted Stereo Mix Recording problem and they could find no fault with it. Furthermore, I tried it and it works! I have an XPS M1730 (Vista 64) that has two headphone ports and a microphone port in close proximity to each other on the front left-hand corner of the machine. Plug one end of a typical 3.5mm mini-stereo patch cord into one of the headphone jacks, and the other end into the microphone jack. What goes out on the headphone jack goes back into the microphone jack. Then, plug a headphone into the spare headphone jack to monitor the audio as the speakers are defeated at that point. That seems to provide the desired results. As I write this, I remember that the portable freeware product, Audacity, recorded only to a monaural track, but I can't remember if the portable freeware product, Waveosaur, had the same shortcoming. The volume needs to be turned up pretty far but the fidelity seems to be great! If you don't have two headphone jacks, a common 3.5mm mini-stereo "Y" adapter plugged into your headphone jack ought to do the trick.
I was worried that the impedance was mismatched enough to stress a component and fry a board, but was assured by the Tech Team that it wasn't the case. After trying it with complete success, I concur. I could not detect any humming in the recording--it appeared clean, and without any ambient noise! It's low tech, but hey, whatever works! Also, it can't hurt that it is a $5 solution!
Thanks for sharing, that's what makes the forum work.
The patch cable idea comes up pretty often -- even earlier in this thread if you care to read through it, but I didn't know that the 2nd headphone jack could be used for monitoring. Thanks for that nugget.
For stereo tracks in Audacity: Edit Menu>Preferences>Adio I/O tab. In the "Channels" dropdown box select "2 (stereo)".
Re impedance, it's line-out to line-in so it would be peculiar to have a mismatch.