Use a built-in firewall if it's available
A firewall program is an application that limits the types of connections that the rest of the world can make to your machine. While this can be very helpful in keeping your machine safe, buying and setting up advanced firewall programs can make using your machine difficult, as they require more computer savvy than automatic updates and Anti-virus applications. However, newer operating systems, and most notably Windows XP and Macintosh OS X, have a built-in firewall that is very easy to use and should not interfere with your normal use.
Windows XP Service Pack 2 includes several new features and upgrades, many of which are dedicated to keeping your machine secure. The firewall becomes much more effective after the installation of the service pack. If you have Service Pack 2 installed, then your firewall should be turned on already. You can confirm this by going to the Security Center, located on the Control Panel.
If you have a version of Windows XP without Service Pack 2, you should run Windows Update right away to ensure that everything on your system is up to date. But before you do, make sure that the firewall is turned on. Click here for instructions on setting up the Windows XP firewall on older versions.
Although most firewalls give users the ability to allow certain types of network traffic that would otherwise be blocked, we strongly recommend not doing so unless you are aware of the risks presented.
To reach this page quickly in the future, use the keyword firewall.
Reporting Security Problems
Send reports of security incidents, attacks, or questions to email@example.com