If you are on a windows PC you may want to download the free version of "Spybot Search & Destroy" version 1.6.2 (the old version). Update and it and run it. That should clear out registry issues. If it doesn't trying running it again as administrator, by right clicking on the icon and selecting "run as administrator."
Here is the download link: http://filehippo.com/download_spybot..._destroy/5168/