Firewall for Windows Server 2003

From: Angus SC2 (a_at_b.com)
Date: 05/21/04 

Date: Fri, 21 May 2004 18:57:30 +0100

Hi, I have a machine running Win Server 2K3 hosted by
http://my.rackspace.com, could someone suggest a firewall that would help
the security of the machine or is the best bet to use myrackspace's costly
hardware firewall system?

Thanks
Angus