On a fairly fresh install of windows 8.1 pro 64bit- I had two devices (card reader and a webcam)that showed with a yellow triangle stating that windows could not start the service due to registry issues (code 19).
Following some other suggestions, I removed the upperFilters entry under the corresponding class entry in the registry and got rid of the code 19 error. The card reader is working. The Logitech webcam 920 pro, now is recognized in windows and works under camera in windows, but has no video in any other software. Both the Logitech quickcam and Skype come up with a black screen. The webcam is recognized and audio does work, so the audio portion of the webcam is working. Just no video or still capture.
I have exhausted most ideas and am looking for suggestions.