The webcam on my Satellite Pro L670-18F PSK3FE which is running Windows 7 64-Bit worked fine until this week. My notifications bar started to say "unknown USB device" and when when I went to use the webcam it was no longer working.
When I turned the webcam off in the BIOS the notification stopped but when I turned it back on the notification kept coming up again. The unknown device is clearly the webcam.
Unknown device means that the driver is not installed.
I think the webcam driver installation should fix this.
Since the face recognition use the webcam too, I recommend uninstalling this tool as well as the old version of webcam software.
Both (or just face recognition) should appear in control panel -> software
Now download the both applications from the driver page.
Start with webcam driver installation:
1) Unzip the webcam driver package
2) The TC30049700N.exe can be unzipped too (right click -> extract here)
3) Now you should see different files exe, dll, and others… try to execute the setup.exe to start the installation. If this does not work, go to device manager, mark the unknown USB device (webcam) and install the driver pointing to the extracted folder containing the webcam driver files. The system should pick up the dll files automatically.
4) Reboot the notebook and follow with face recognition software.