PC Tools Firewall Plus 4 for Windows

PC Tools Firewall Plus is a powerful free personal firewall for Windows® that protects your computer by preventing unauthorized users from gaining access to your computer through the Internet or a network. By monitoring applications that connect to the network Firewall Plus can stop Trojans, backdoors, keyloggers and other malware from damaging your computer and stealing your private information.

PC Tools Firewall Plus is advanced technology designed especially for people, not just experts. Powerful prevention against attacks and known exploits is activated by default while experienced users can optionally create their own advanced packet filtering rules, including IPv6 support, to customize the network defenses. All you need to do is install it for immediate and automatic ongoing protection.

Available for download at this link.