Agree about not having too many antis, I`ve got those I mentioned plus Webroot Spysweeper, Spyware Doctor, CWShredder etc. I was pointing out a minimum of those.
Having said all that my daughter managed to catch the Serflog.worm 2wks ago through Messenger, the very day it was released. It just shows, you can never be too careful.
To disable the XP firewall depends upon whether you are running Service Pack 2 as this detects if you have a choice of Firewalls and would have asked you to make the choice when you first installed it.
If you are still on SP1 go into Internet Connections/properties, then select the Advanced tab where it will let you enable/disable the XP Firewall.
Keep Spydoctor and make sure you update and run it regularly.It`s one of the best antis.