Wow - that's a bad case.
Have you got a backup of your data? If so, a clean install of XP would be best.
Install a free AV program such as Avast;; a few free malware checkers and a decent firewall such as Kerio / ZoneAlarm.
These, together with a regular clean up routine will do all that Norton does.
Then call symantec and take up their 30 day refund on unwanted products.