Norton is the very devil for slowing down your pc and hogging resources.
I suggest you disconnect from the internet, turn off Norton and turn on your Windows Firewall and antivirus until you get something better.
Now remove Norton through the Add/Remove programs.
Now go back on line and download the Norton removal tool:
http://www.softpedia.com/get/Tweak/Uninstaller s/Norton-Removal-Tool.shtml
Follow the instructions and you should now be Norton free.
Then you will need to install a reliable firewall and anti-virus.
I recommend ZoneAlarm OR Commodo firewall.
AVG OR Avast anti- virus.
All free and downloadable from here:
http://cgi3.ebay.co.uk/ws/eBayISAPI.dll?ViewUs erPage&userid=cuddly-hippo