ALTERING WINDOWS FIREWALL'S DEFAULT SETTINGS VIA AN INF FILE

The Windows Firewall that comes with Windows XP Service Pack 2 is a stateful host firewall. It discards all unsolicited incoming traffic that doesn't correspond to either traffic sent in response to a request by the computer, or unsolicited traffic that has been specified as allowed via Exceptions, thus providing a good level of protection against malicious users or programs. It's also pretty flexible; you can easily configure a number of options via the Windows Firewall interface, which is available in the Control Panel.

Visiting every Windows XP system in order to make changes in this fashion isn't practical. Fortunately, you can make adjustments to the Windows Firewall's default configuration by editing the Windows Firewall INF file, Netfw.inf. Then, you can roll out the changes simply by distributing an edited copy of this file.