Understanding Windows Firewall

A firewall is a system or software that controls the flow of traffic between networks and protects your computer or network from an attacker who might damage or get access to your personal information. This extra layer of protection is especially important if your computer has an “always on” Internet connection such as a cable modem or a DSL line. When someone on the Internet or a network tries to connect to your computer, Windows Firewall blocks the unsolicited connection. If you run a program such as an instant messaging program, the firewall will ask if you want to block or unblock the connection. If you choose to unblock the connection, WindowsFirewall creates an exception so that the firewall won’t bother you when that program needs to receive information in the future.

Windows Vista and 7 install and enable the Windows Firewall by default.

The Windows Firewall does not:

• Detect or disable computer viruses and worms if they are already on your computer. However, it will help block computer viruses and worms from reaching your computer.
• Stop you from opening email with dangerous attachments.
• Block spam or unsolicited email from appearing in your inbox.

The Windows Firewall is designed to prevent unsolicited connections from reaching or originating from your computer, and so you may have to configure it to allow connections for certain programs and services. If this is the case, you can make exceptions in the Windows Firewall for those programs. Never allow an exception for a program that you don’t recognize.

Windows XP Note: Windows XP Service Pack 2 must be installed in order to see the Windows Firewall icon in the Control Panel.

Click the button screenshot to see the simulation for viewing the options on the Exceptions tab in the Windows Firewall dialog box.

Windows XP

Windows Vista

Windows 7