I know it's not freeware, however, I downloaded a trial (15 days) & must say I am very impressed.
It works so well, it uses 200mb of ram less and feels very smooth.
I recommend people give it a try, don't forget to make a backup first.
http://www.majorgeeks.com/Norton_360_d5377.html
Tips are remove spy bot search and destroy first, then windows defender beta, reboot, uninstall from add remove programs NIS, NAV or NPF which ever you have.
Reboot and then install Norton 360
