My notebook is HP ProBook 4540S with a built in WebCam spec'd at 720P.  I have Movie Maker 2012 version and Windows 7.

In the Project Tab, I select 16:9.  When I record on the webcam, I get the vertical black bars, because it is constraining the recording to the 4:3 aspect ratio for some reason.

I opened skype to confirm resolution of my camera, and it appears to be 16:9.

If I open a movie file recorded in HD on my DSLR, Movie Maker displays it fine in 16:9 - correctly. 

I can't find a way to make Movie Maker let me record from the built-in webcam in 720 format.  What am I missing?