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.