Hi there Cameron,
If you are referring to the Windows XP's built-in
firewall, then make sure the dependency services for
Internet Connection firewall are all enabled.
* Click Start, choose Run, type "services.msc" (with out
quotation marks) and click OK.
* In the corresponding window you will see a list of
services.
* Scroll down and double-click the Internet Connection
Firewall service.
* Choose Dependencies tab to see the list of dependency
services for Internet Connection Firewall service. You
will see the following services:
Application Layer Gateway service
Network Connections
Network Layer awareness
Remote Access Connection Manager
Make a note of the above services and follow below steps
to enable them:
* Click Start, choose Run, type "services.msc" (with out
quotation marks) and click OK.
* In the corresponding window you will see a list of
services.
* Double-click the "Application Layer Gateway service,"
under startup type choose Automatic.
Make similar modifications for rest of the 3 services.
Once you are done performing the above steps. Perform the
below steps to enable the Internet connection firewall:
1. Run the Network Setup Wizard by following these steps:
a. Click Start and select Control Panel.
b. Double-click Network and Internet Connections.
c. Click "Setup or change your home or small office
network."
2. In the wizard, choose a configuration that indicates
that your
computer is connected directly to the Internet.
The Internet Connection Firewall will now be enabled.
HTH
Arjun