The error the user was getting:

Due to an unidentified problem, Windows cannot display Windows Firewall settings.

We found a well detailed solution at:

http://windowsxp.mvps.org/sharedaccess.htm

Symptoms

•  When you open Services.msc applet (Start>Run>services.msc>OK), the Windows Firewall/Internet Connection Sharing (ICS) service may not be available in the listing
•  Windows Firewall/Internet Connection Sharing (ICS) service is available in Services listing, but you are unable to start the service
• You receive the following error message while accessing the firewall settings (firewall.cpl or opening "firewall" from within the control panel)

Due to an unidentified problem, Windows cannot display Windows Firewall settings.

Cause

This happens due to missing or corrupt SharedAccess reg key, which represents the Windows Firewall Service.

Resolution: Right-click the file sharedaccess.reg and choose "Save Link As" (Firefox) or "Save Target  As" (Internet Explorer).

This is only for systems running Windows XP Service Pack 2, save the file to your Desktop. Then double-click (or right-click and choose to "merge") the file to merge the contents to the registry. The Services entry will be created. Restart Windows (mandatory step, otherwise the following NETSH command will display an error message). After restarting Windows, run this from Command Prompt (Start>Run>tyoe in the "cmd" (without the quotes), then press the [OK] button.

NETSH FIREWALL RESET

Launch firewall applet from Control Panel, and then configure your Windows Firewall settings.

If nothing helps, as a last-resort solution (before reinstalling Windows XP Service Pack 2), give these two commands a try. Click Start, Run and type:

rundll32 setupapi,InstallHinfSection Ndi-Steelhead 132 %windir%\inf\netrass.inf

Restart Windows, and then run this command (from Command Prompt):

NETSH FIREWALL RESET

Attempt to start Firewall applet. Start the Windows Firewall service if prompted.