Get a program such as Ad-Aware (
http://www.lavasoft.de - Free Trial)
or Spybot (
http://www.safer-networking.org/ - Freeware (I believe)
These programs are more sophisticated and can check the memory (At startup) before the Adware can load it's self into your memory and give Norton (Or anything else that's not specifically designed to remove Ad/malware) a hard time removing it.
Good luck in your endeavours..
Raptor