I am attempting to re-set up my Dimension E510 following a move, but I am having some issues with accessing the internet.  My wireless network was set up by my local cable installer, which I have effectively used to connect to the internet with my laptop and my Samsung smartphone.  I connected the desktop via a LAN portal on my new Belkin Router, and it appears to be connected to the internet; however, I keep getting "Issues with security certificate" (using Firefox) and "No Internet Connection" when I attempt to update my Norton 360 Premier to my latest version.  Any thoughts or suggestions would be greatly appreciated.  Thanks!