If you can't uninstall Silverlight using the classic way through Control panel, then I recommend you run the official Microsoft Fix It tool developed exactly for this process. Visit the page linked below and download the Fix It tool. Launch it with administrator access and let it fix the problems. Restart the computer and then you should be able to remove Silverlight.
As an additional recommendation, re-install Silverlight then remove it. It should work in most of the cases, not only Silverlight but with other apps as well.