I believe that reinfecting a system during a system restore depends on what is meant by restore. If using Windows System Restore it is possible to reinfect if a restore point is infected, but if one is restoring the system back to the original state that it was in when purchased, I think that is a different matter.
What I use isn't free, but I have used ZoneAlarm Antivirus/Firewall for many years and love it. You can get the firewall for free however and I agree that the Windows firewall is not adequate.
Edited by Stang777, 07 December 2009 - 11:43 PM.