If I shut down ZA (and set it to stay off), I can't turn on
Windows Firewall because on the WF configuration page, all the options are grayed out and it says, "For your security, some settings are controlled by group policy."
I'm running Windows XP Home SP2. I found a registry key that controls this group policy, (HKLM\Software\Policies\Microsoft\WindowsFirewall) , and deleted the key as per instructions I've seen on the web. However, the key keeps coming back, and I still can't enable Windows Firewall.
I understand that some viruses and trojans try to manipulate this key, but I've scanned my PC extensively for viruses and spyware, and found none.
Is ZA doing this, even though I've shut it down? I don't want to uninstall ZA to find out. Do you know?

Operating System:Windows XP Home Edition
Software Version:7.0
Product Name:ZoneAlarm (Free)