Download ZoneProtect Personal Firewall
ZoneProtect Personal Firewall is a completely free software that will protect your computer and let you surf the web in a secure way. Even though it doesn't cost a penny, this firewall is so powerful you won't have to worry about intruders issues while surfing in the Internet.
ZoneProtect Personal Firewall configures to work automatically and will detect any dangerous intruders that want to connect to your network. It's simple to use and it has a neat and clean interface. It doesn't consume a lot of your system resources so it won't crash your computer.
Its compatible with most Windows Operating Systems from NT to XP.