For registering DLL file through right click on it,just download the Rightclick registry file and run it.(I advise-Pl take a back up of Registry entries before running this file)To take a backup of Registry files:
Start-Run -regedit
In Registry Editor:
File-Export.-Save the registry files in the name you want.In case something goes wrong,you can restore this.
Click the below button to download Rightclick registry entries file.
-Shivaram