I have been using Kerio 2.1.5 for over 6 months and I love it. Unfortunately, I may be upgrading my OS soon (Vista, Windows 7, who knows) and I am afraid of any incompatibilities with this great program. One such conflict that most people know of is PerfectDisk. Are there any other free recommended firewalls like Kerio that is free and more recent? Agnitum Outpost was a past favorite until I found out how light Kerio is. It needs to be rules based with customizable rules on the fly when any inbound/outbound request is made, like Outpost and Kerio. Thanks for any suggestions.