Windows cannot display Windows Firewall settings

I make an update with my XP machine and install a service pack 2.
After a successful update installation reboots my computer. When my team was the shift of noticed that my windows firewall is running.
I try to switch on, but I get this message "due to an unidentified problem, Windows cannot display the Windows Firewall settings' .
I read in a forum that the cause of this error is due to missing or damaged shared access registry key, which represents the Windows Firewall service.
Try to find a solution there.
Download shared access.reg and save to the desktop, double-click on the combination of file the contents of the registry and restart the computer.
After restarting attempt to check if the problem is solved but unfortunately did not work again.
How do I fix this problem?
Are there any other solution?
