NIS 2012

Hi

Have had NIS2012 installed for some time and everything fine.  Lately had some Broadband connection problems and had to get an engineer to check my router and he had to remove all Norton products to get my connection back.  He couldn't identify why Norton would not allow internet connection.  Have tried re-installing NIS today and once again I find I am unable to connect to broadband even though my router says it's connected.  Had to use the removal tool again to get going.

As far as I am aware I haven't changed any personal settings.  Why should Norton affect my connection?  What am I doing wrong?

Any help appreciated. Thanks