Take simple steps to engage its protection, or try a more powerful defense.

When you're online, your computer passes information to and from the Internet through ports, or open connections. A port's number identifies the type of information passing through it. For example, port 80 is used for HTTP traffic, so page requests and webpages being downloaded all come through port 80.

Hackers usually try to sneak into your computer through an unguarded and open port. Luckily, Microsoft's Windows XP Internet Connection Firewall helps you close ports you aren't using.

Here's how to enable the XP firewall:

  1. Log into XP with an owner account.
  2. Click the Start button and select Control Panel. Double-click the Network Connections icon.
  3. In the Network Connections window, click to highlight the connection you want to protect. In the left panel, under Network Tasks, click "change settings of this connection."
  4. When the connection status dialog box opens, click the Properties button.
  5. In the Properties dialog box, click the Advanced tab. Check the box beneath "Internet Connection Firewall." If you leave it unchecked, the firewall is off. If you aren't running any servers on your computer, just click OK. If you run an FTP or Web server, you need to change the advanced settings.


For more help, visit Microsoft's Internet Connection Firewall pages.

Some geeks think Microsoft's XP Firewall is underpowered. They prefer more powerful software, such as BlackICE Defender. Others hide their networks behind a cable/DSL router like the Linksys BEFSR41, which includes a built-in hardware firewall.