More recent versions of Windows can block files that have been downloaded from the internet, but you can just right click on the file, open up Properties, and click on the Unblock button to unblock the file.
Not being a Norton anti-virus user, I can't say what exactly Norton is doing. If you're still having trouble after checking whether Windows is blocking the file and fixing that, could you disable Norton for a moment and then download and install H9 Control?
