Simple Firewall

[G Farnham <gfarnham () gmail com>]

Does anyone know of a real simple software firewall for Windows 2003 Server?

The application is for a game server.  Basically, the server needs to
send udp in and out of the server as fast as possible for 50 or so
clients running a first person shooter.

All I need the firewall to do is check the source IP against a deny
list and either deny or permit it.  

The goal is to have a minimum impact on performance as latency is
everything in online gaming.
Norton,  Macafee, ZoneAlarm, etc all seem to be to bloated.
Don't need any checking on outbound
Don't need any checking based on port

The built in firewall and IP filtering do not support a deny list. 
WinXP SP2 is not applicable as this is Win 2003 Server.

This is for a hosted server, so I can't add any hardware.

GDF