Windows 2003 "Windows cannot display Windows firewall settings"

Our Windows Server 2003 SP2 has been hit by a hacker that installed a few services and other niceties and disabled our firewall.

I've managed to clean up (the strange thing is that no detection software I used was able to find anything wrong) but the firewall is still down and I'm getting the above error when trying to open its configuration.

I've followed a few links but nothing seems to work. Is there a way to re-install it?

Stuff I tried:

• Change Windows Firewall settings
• http://www.chicagotech.net/Security/xpfirewall1.htm

From serverfault Renaud Bompuis

• If your server was really hit by a relatively adept intruder, you need to wipe and re-image it. There's no telling what he or she may have done or planted, not to mention that the time required to be reasonably sure of successful "cleanup" would take longer than rebuilding a server.

  From phoebus