Klaus,
I have used USBDeview as suggested and discovered no obvious conflicts. There were two other USB video device drivers, not in use, from previous webcam installs which I removed using the tool, however, the behavior did not change. I also, for completeness, disconnected another camera that is on the system and used for general monitoring with another application, and tried again. As has become the expectation, the video plugin window froze almost immediately upon opening. Do you have any other experiments or suggestions?
Thank you,
Steve