Norton is famous for causing conflicts when it is updated or uninstalled.
Seems to leave a piece here and there and internet access is trashed.
Go to the Symantec site and download free Norton removal tool.
Use any computer with internet access and save it to a thumb drive.
then run the tool on your computer that doesn't connect.
Restart and give it a whirl.
Beats digging around in th sys and reg files for all those little bits and pieces that
get left behind on a straight uninstall.