I ran across this some months ago and have used it with great success. As you all know the latest update from MS regarding the Blaster Worm states that you should turn on the local firewall built into Windows XP but once you do that, how do you know what's happening on the firewall.
Once the firewall is enabled you must enable logging to see what's going on but that turns out to be a huge log file full of crypt stuff that a lot of people can't read or understand.
So.. in steps a Windows XP Log Reader which offers the sweetest log viewer that everyone can understand plus, it's free.
www.winoscentral.com/windowsxp/fwlog.php
Ums kurz zu fassen und in Deutsch

Das ist ein Programm womit man die Logs die durch die XP Firewall angelegt werden, angezeigt werden können... endlich wird die Arbeit der XP Firewall transparenter
Mfg Oliver