Files can be shared, but not the Internet

Ladies and Gentlemen:

The majority of the computers within my network are connected through a wireless router. However, there is one computer that I own (Windows ME) that connects to the main host computer (Windows XP Pro SP2) through a phone line network.

I have gotten the connection between the 2 computers to be able to ping each other, as well as share files and printers. The only problem I am having is getting the computer on the phone line network to connect to the internet through the main host computer. Internet Connection Sharing is enabled on the Local Area Connection that connects to the Internet through the Wireless Router, and the IP settings of both computers are configured properly.

I have reason to believe that my problem exists within my Windows Firewall settings. Unfortunately, I am unable to disable my Windows Firewall because the option boxes to turn the firewall on or off is grayed out.

I have searched through previous posts to find something related to my problem, but I could not find anything (or think of proper search terms to bring up a possible solution).

Can anyone suggest any solutions?

Thank you for your time,

 

I presume you mean the "off" check box in control panel / security center / windows firewall settings.

This is because you are using Internet connection sharing.
ICS is part of the
Windows Firewall/ Internet Connection Sharing Service
if you go to start/ run and type services.msc and hit enter

Try going to control panel / security center/ windows firewall/ exceptions and check them all
Then go to the advanced tab and under network connection settings choose the one (probably your lan ) and remove the check mark.