invading? i highly doubt that. its an antivirus program not some trojan or other bug you get.
now if you did not uninstall the program correctly then perhaps you do still get windows popping up to renew/buy or you have clashes with your current antivirus. if you did an uninstall already perhaps there are system files left behind. try a "fully remove norton *program here*" search into google where you insert your particular products name between the *. if you still cannot get things to work... a wipe and reinstall will fix pretty much any issues, though i doubt you need to go that far.