Welcome and Happy New Year 2019!
So, a few years back, I have bought the C920-C which is the business version of the C920 HD consumer version. The main difference is, it was not coming with software of any sorts and is also reffered to as “Logitech C920-C Webcam for Cisco”
While the consumer version was supported in Windows 7 and up, the business version was relying on the codec support built in Windows 8.1 and Windows 10 to work.
I found out by checking it again that Logitech changed this. on December 18th, 2018 they have released the new “Logitech Capture” software which adds support for Windows 7 and adds the software you previously did not have for this model: https://support.logitech.com/en_us/product/c920-c-webcam/downloads
In my case, I had to restart the PC afterwards and let the device manager search for drivers automatically for the camera and it found the driver shipped with this software package for Windows 7 x64! 🙂
Nice move, Logitech!