Sygate Personal Firewall is FREE for Personal Use
System Requirements:
Pentium 133 or equivalent 32 MB RAM
10 MB free disk space
A Dial-up Analog modem, ISDN modem, or a Network Interface Card with DSL, DirecPC, Cable Modem or other Internet connection.
Internet access via network interface card or a working dial-up Internet account with an ISP (Internet Service Provider).
Internet Explorer Version 4.0 or later

Operating Systems:

Windows XP
Windows 95, 95 OSR1, 95 OSR2, 95 OSR2.5 with Winsock 2 and DUN 1.3
Windows 98, 98 Second Edition
Windows Millennium Edition (ME)
Windows NT 4.0 Workstation with SP5 or later
Windows NT 4.0 Server with SP5 or later
Windows NT 4.0 Terminal Server with SP5 or later
Windows 2000 Professional, Server, Advanced Server, Data Center

Features:

Windows XP Support
Customizable Advanced Firewall Rules
Ability to Configure Global Settings such as trusted IP addresses
User-friendly Rule Viewer & Rule Editor
Message Console to display security alerts and system information
Unique Dynamic Help System assists users with rule creation
Enhanced ability to capture and log packets per rule
Ability to control incoming and outgoing ICMP packets by type
ICS Support for Ethernet connections with Windows 98 SE.

Sygate® Personal Firewall is not compatible with optional Internet Connection Sharing Software included with Windows ME or Windows 2000. By default, ICS is not enabled. We do not recommend enabling Microsoft's Internet Connection Sharing option on computers running this version of Sygate® Personal Firewall.