I've had issues with anti-spam software really eating resources. I'm not a Norton fan, one of the reasons was their heavy footprint, don't know if that has changed.
+1 with Alf on Spybot Search and Destroy.
http://www.safer-networking.org/en/index.html
Download a free copy and run.
I'd also question your Internet connection. The amount of time to bring up a profile page seems unreasonably slow and not CPU dependent.