I am currently running CIS v3.14 (no AV) with Avast 5. I've been thinking about moving from CIS as I really don't like where they're headed with v4. I would prefer to stick with freeware. My choices appear to be Outpost or Private Firewall as PC Tools does not appear to compatible with XPx64. Maybe I should wait for the 64 bit version of Online Armor. My only real concern here is that my choice plays nicely with XPx64 (reasonable overhead, no slowdowns or driver conflicts...) If anyone here has direct experience with any of the above and XPx64, I would certainly appreciate your input.