Protect Your Computer With Firewall

Helping to protect your computer with a firewall

Why you need a firewall. A firewall is a protective boundary between a computer (or a network of computers) and the outside world, where people or programs might try to access your computer without invitation. Hackers commonly use software that scans the Internet looking for computers with unprotected Internet connections. This software sends a very small message to your computer. If your computer does not have a firewall, your computer will automatically answer the message and thus announce that it is unprotected. But if you have set up a firewall, it will receive such messages and not answer them, so hackers won't even know that your computer exists.

Firewalls can be either hardware or software. A hardware firewall is a piece of equipment that you physically connect to your network. It monitors all aspects of the communications that are sent and received, and inspects the source and destination address of each message that it handles. This provides security in helping to prevent intrusions to your computer or network. A software firewallperforms a similar function by using a program inside your computer instead of an external device.

Microsoft Windows XP Service Pack 2 (SP2) has a software firewall that's built in and turned on for you. This firewall, called Windows Firewall, is turned on by default so that a level of protection is in place right away. It monitors communications in the same way a hardware firewall does. Windows Firewall restricts information that comes to your computer from other computers, giving you more control over access to your data, and providing a line of defense against people or programs that try to access your computer without invitation. Regardless of whether you choose to take advantage of the Windows Firewall or another firewall available to you, keeping the firewall turned on and updated is one of the important keys to helping to protect your computer's security.

Hardware and software firewalls can be used on the same computer. By default, Windows Firewall is enabled on all connections.

Click Related Topics for information about how to:

• Understand how Windows Firewall works.
• Enable or disable Windows Firewall.