One more test done:
on Dell's diagnostics page, I tried 'hardware -> camera' and PC-Doctor responded 'A diagnostic category was specified and the applicable device does not exist.'
When trying diagnostics on 'symptom: webcam', PC-Doctor tested only the microphone, which works fine.
I have read elsewhere that one should use the Microsoft driver for the webcam in WIndows 8. Which one, and where to find the one appropriate for this webcam on this machine?
