ZoneAlarm is probably the most well-known of firewalls, partly because it's free for personal use, but also because it's effective and very simple to use. This latest version now works with Windows Vista. The download is a small utility that is used to select the correct version of ZoneAlarm for with Vista or Windows XP and 2000.

Its main appeal stems from the fact that you can install it and forget about it, yet be securely protected from outside intrusions or attacks.

Wizards make the installation as painless as possible, and ZoneAlarm will remember your preferences once specified.

In other words, give permission for a program to access the internet and it will always allow it access in the future (unless you specify otherwise, of course).

When in Stealth Mode, ZoneAlarm renders your PC invisible on the internet, increasing your security and privacy.

The latest ZoneAlarm 7 contains a major update to the firewall engine, including support for malware blocking capabilities, an auto-learn feature and better protection against sophisticated threats

Note that this is the basic and free version. It will download to your computer as a 'stub' and ask you if you want to install the Windows 2000/XP or Vista version of ZoneAlarm. Once you make your choice, the installer will then download the correct installer (which is 18MB).

Note that the software revision may differ between Vista and XP/2000, depending on your operating system