Symptoms
When you open Services.msc applet, 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)

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
Download sharedaccess.reg (only for systems running Windows XP
Service Pack 2) and save to Desktop. Then double-click 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 (cmd.exe)

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.