I searched for this topic here and found what looked like a good solution:
finding out which app is using the webcam
I went through all the steps, and Process Explorer indicated that CameraHelper.exe was using it. I thought that by killing that process in Task Manager would resolve the issue.
I've been using a Logitech C920 webcam for a few years; it previously worked great.
This week it stopped working on my Dell XPS 9100 running Win 7 Pro 64x. I tried it on two other machines and the camera itself is fine.
It still shows up in Device Manager as working properly. In Sound, it's shown as the default microphone.
I uninstalled and reinstalled the driver.
It's USB, but it's not a USB issue: no matter which port I use it shows up.
When I launch the Logitech software it says:
"We detect your camera is either disconnected or being used by another application, try closing any other application(s) that might be using your camera and then restart Logitech Capture."
Somehow I think a setting in Windows 7 got corrupted and something seems to be blocking access.
I use this to give classes as part of my job, so fixing it is urgent.
Any suggestions of what to check would be greatly appreciated.
