What does Windows XP ICS/ICF status mean?
Internet Connection Sharing is where two or more computers share the same Internet connection. An Internet Connection Firewall is a Windows XP-specific feature that monitors and limits incoming Internet traffic. ICS and ICF can be enabled independently, which means you can have ICF turned on and ICS off, or vice versa.
If you are sharing an Internet connection, ICF should only be enabled for the computer or router that is directly connected to your Internet connection. It should not be configured for each computer on the network. If you only have one computer connected to the Internet, you can enable ICF directly on that machine and ICS is not needed.
The ICS/ICF status refers to whether or not either of the two options have been turned on.