Mark, thank you for being a resource on here!
Having VERY similar issue on same laptop... HP Envy Windows 10.
I installed Skype on the laptop, and while it was installing, I think that's when I disconnected the WebCam. I already tried restoring it back to the day prior to downloading Skype.
Error Messages Below:
My issue/error message is saying that my device (name: HP Wide Vision HD Camera) ) is "disconnected" to the computer (Code 45).
1st screen shot: Device Manager>Properties>"General" Tab
2nd screen shot: Selecting "Camera" from the Windows Start Up Menu bar