Q:

What happened to my "Predefined rules" in Windows Firewall? How can I get them back?

Windows Firewall Advanced Settings in Windows 7 , has predefined rule sets. 
When I click the "Add Rule..." button in my Windows 7 Ultimate install, it looks like this: 

But, on a machine I have that runs Windows 7 Home Premium, when I click "Add Rule...", the "predefined rules" option is greyed out.  Like this:

Is this expected?
Does Win7 Home Premium NOT have predefined rules?
How can I get the rules back?

A:

I don't know exactly what happened to the predefined rules, but I see three possibilities:

another Security suite which includes a firewall - McAfcee - had been installed on the system. When installed, it removed all the pre-defined rules. McAfee's security suite has since been removed from the PC, but the pre-defined rules did not re-appear. 
the Home versions of Windows 7 simply don't get predefined rules. I find this less likely, only because security is such a huge focus of Microsoft.  
there was a virus that removed all these rules. 

I don't know which of these, if any, is the actual reason the predefined rules are gone. I don't have a virgin Win7 Home Premium to examine, and I don't have the full forensic records of the Win7 Home Premium system. In any case, it doesn't matter. 
After some spelunking, I found that the predefined rules for Windows Firewall on Windows 7 installs that do have predefined rules are stored in the Windows Registry at: 

[HKLM\SYSTEM\CurrentControlSet\services\SharedAccess\Defaults\FirewallPolicy\FirewallRules]

On my Win7 Home Premium machine, I looked in that key and found.... nothing?  The key hierarchy was there, but no values.  
I got the pre-defined rules to appear (re-appear?) on my Win7 Home Premium machine by following these steps: 

On the Win7 Home Premium machine, run services.msc and stop Windows Firewall
On the Win7 Ultimate machine, open regedit, go to the specified key, and export it. 
transfer the .reg file to the Win7 Home Premium machine
on the Win7 Home Premium machine, run Regedit, and Import the .reg file
Reboot the Win7 Home Premium machine
on restart, open Windows Firewall Advanced Settings, click the Add Rule... button, and view the predefined rules.

I hope this helps someone else.
As always, when modifying the registry, be super careful and back everything up prior to making modifications. 

A:

Huge thanks for this post - helped me fix a problem with broken file and print sharing.
I had also uninstalled McAfee from the problem Windows 7 machine a few days before the problem became apparent. That machine had been infected by a firewall attacking virus a few months earlier while under McAfee's "protection" but it may have been that virus that removed the default rules, rather than McAfee's installer - as you suggest the problem may only have shown up when McAfee's firewall was uninstalled.
I exported the predefined rules from a Windows 7 Starter (netbook) machine, so don't think they are specific to any version of windows. I exported everything from "Default" downwards, because none of it was there.
Note also that I needed to manually enable new Incoming Rules for File and Print Sharing, and Network Discovery in Windows Firewall to get things going afterward.

