http://constantguard.comcast.net/products-and

http://constantguard.comcast.net/products-and-services/norton-security-suite//
The only option is to save the file and then you need to run the installer which produces the next screen shot;
You have to uncheck the XFINITY Toolbar option so you don’t install it. After clicking NEXT you are redirected to the
Norton site that downloads the NSS.