NAV 2010 installed and now unable to use internet

Hi i installed Norton Anti-Virus 2010 yesterday and ever since i've found myself unable to use the internet on the computer its installed on... are their any features that would be blocking it? I've tried ringing the company that provide the internet in case it wasn't Norton and their was no problem there end plus i can plug the net onto my laptop without any problem. The only change since the internet stopped working was that Norton was installed.

 

 

[edit: Clarified subject.]