Virusattractor-
Along with spybot 1.3 you should install spyware blaster and guard.
Also i didn’t see a firewall in the list, if you are using the one in XP, get a better one.
Try using Firefox instead of IE6 and Thunderbird instead of Outlook or OE6.They will help you to be more secure.
I also use KL-Detector,Bazooka+Ad-aware.
Make a backup of the registry and then use a cleaner. There are many out there.
If you like to download stuff and try them out,I reccomend using a different computer that you can disconnect from network so if it gets sick, it won’t affect anything.(that’s what I do ;D
-max