Windows 7: Windows Media Encoder: No Specified Device Driver Is Present

I had downloaded Microsoft Windows Media Encoder (WME) 9.0.  I was aware that it was unsupported and otherwise limited in comparison against Microsoft Expression Encoder 4 Pro ($199).  I was trying to use it to do video screen capture in 64-bit Windows 7.  I went into New Session > Capture Screen > Specific Window and Capture Audio from the Default Audio Device > designate the window > name the output file > high quality > diplay information (blank) > Finish.  At that point, I got this error:

Windows Media Encoder

No specified device driver is present.(0xC00D0072)

A search led to a Microsoft webpage that said this occurred because DirectX Media 6.0 was not installed.  Unfortunately, the page to which they directed me for the appropriate download was defunct.  Wikipedia said that DirectX 6.0 was released in August 1998, that the current version was DirectX 11, and that DirectX had been included in Windows ever since Windows 95 SR2.  (I also saw an indication that this problem might arise only when trying to record audio along with the video.  I didn't investigate that; I was only interested in video plus sound at this point.)

My theory was that DirectX had grown and that WME had not been maintained to keep up with it, and therefore I needed to install an older version of DirectX for that purpose.  I was not sure that this would work without screwing up the more recent DirectX.  I made a System Restore point and then downloaded DirectX 8.1 Runtime for Windows 2000, released in November 2001.  I wasn't sure whether that was the right thing; I also downloaded the DirectX Media Platform SDK Redistributable (June 2001).  Both were around 6-8MB.

Before installing them, I looked at a few more posts.  One post said that what was missing was actually a WDM (Windows Driver Model?) driver for the microphone.  The plausible theory in this case was that I would gain nothing by installing a retrograde version of DirectX; instead, I just needed a current driver.  But I was using onboard audio; I had only installed the motherboard recently; and I had made sure to get the latest drivers at that point.  I guessed that the motherboard drivers were no longer attempting compatibility with WME.

There was always the option of using a handheld audio recorder to record sound from the speakers.  Or if I didn't mind risking blowing up my handheld recorder, I could try running a cable directly from the computer's headphone output to the recorder's microphone input.  I would still have the hassle of synchronizing audio with video in a video editor.  That would be more difficult if the video showed lip motion or other things that would become bothersome if they weren't closely aligned.

There was also the possibility of doing further research into who was using WME on Win7 successfully at this point, and what hardware they were using, and buying the appropriate sound card.  I was out of time for this project, but it could also develop that further research would turn up a solution I had overlooked.  But good video capture had been elusive.  I had bought Debut and had been using it with good results; the question only arose because there was a hopefully temporary licensing snafu where Debut didn't work for me in the middle of the night.  Debut was now working again, so I shelved this question for the time being.