Precision M4700 microphone and webcam not working after windows 10 upgrade

Hi 

The integrated microphone and webcam on my precision M4700 has simply gone kaput after a windows 10 upgrade. The camera is not even detected.

I see that many have faced the situation with no solution . The sad part is the windows upgrade assistant let me proceed with the windows 10 upgrade with absolutely no issues and then this happens. 

I have tried all possible solutions from Resetting windows 10 , running windows 7 compatible drivers etc to no avail. 

Would really be helpful , if someone can let know if the issue is a known issue or if there is any solution to it ,so that atleast others won't have to waste their time troubleshooting.

Thanks & Regards

Girija