Keep your firewall turned on

What is a firewall?

A firewall helps protect your computer from hackers who might try to delete information, crash your computer, or even steal your passwords or credit card numbers. Make sure your firewall is always turned on.
Windows XP comes with Internet Connection Firewall, but you must turn it on to use it.
To turn on Internet Connection Firewall:
1. Point to Control Panel, double-click Network and Internet Connections, and then click Set up or change your home or small office network.
2. Follow the steps in the Network Setup Wizard to turn on the Internet Connection Firewall.
When you choose a configuration in the wizard that indicates that your computer is connected directly to the Internet, the Internet Connection Firewall is turned on.
Windows XP Service Pack 2 (SP2) and Windows Vista come with Windows Firewall automatically turned on. Visit Microsoft Update to download Windows XP SP2 for free. Visit the Windows Vista home page for more information about the newest operating system from Microsoft.

What are operating system updates?

High priority updates are critical to the security and reliability of your computer. They offer the latest protection against malicious online activities. Microsoft provides new updates, as necessary, on the second Tuesday of the month.