Free personal firewalls
ZoneAlarm 6.0 is a free personal firewall program that protects
your computer against any type of unauthorized connections to your
SoftPerfect Personal Firewall
SoftPerfect Personal Firewall is a free network firewall designed to protect your PC against attacks from the Internet or via a local area network.
SmoothWall Express is an open source firewall distribution based on the GNU/Linux operating system. Linux is the ideal choice for security systems; it is well proven, secure, highly configurable and freely††† available as open source code.
ABC Security Protector
This nice free security utility enables you to protect your PC by disabling some features like: use of the MS-DOS command prompt in Windows and real mode DOS applications from within the Windows shell, and disable function keys on boot up like the F5, F6 and F8 keys. The program is very useful if you want to disable the lowlevel access to your system. It's easy to use, excellent online help is also available.
Open source software with easy to use graphical interface with powerful features for Linux desktop users and system administrators.
Sygate Personal Firewall
FREE for personal use, Sygate Personal Firewall 5.x provides best of breed security in a user friendly interface, protecting your PC from hackers, trojans and DoS attacks.
WyvernWorks Firewall is freeware that protects your computer from being attacked via its ports. You can add an unlimited number of ports to the firewall protection list. Once installed, WyvernWorks Firewall is located in the system tray and blocks unauthorized inbound and outbound traffic. If someone tries to hack into your network, WyvernWorks Firewall alerts you to the attempt and includes the Internet Protocol (IP) address of the perpetrator.
Protect your server from intrusion. When you run a server on your machine, it uses "ports" to allow other machines to connect to it. You might be running the server just for internal use, yet there's no easy way to stop someone outside from accessing the server. AnalogX PortBlocker lets you block the Internet port of most servers, making them unreachable to other computers on the Internet. In addition to blocking your ports, you can log any access attempts made by other machines.