Well, this has taken a while, including one chat and one phone call with MS technical people.
While I watched them attempt to update my integrated camera's driver -- all to no avail -- I did notice that under "select device driver from those on this machine" or some such there was, in addition to "Integrated Camera", a "USB Video Driver". When I selected that as the driver for my camera, it started to function properly.
I hope that others with a problem similar to mine might find this option useful.