ICF is a Windows XP feature that protects Internet-connected computers from unauthorized access.
The full-form of ICF is the “Internet Connection Firewall.” When ICF is enabled on a computer, Windows keeps a log of all incoming requests from other systems on the Internet.
If a request has been requested by the user, such as a web page, then the transmission will not be affected in any way. But if the request is a bit unsolicited or unauthorized or cannot be recognized by the system, then the transmission is dropped.
This is because it prevents any hacker intrusion or intrusion of malicious software such as Spyware from damaging the computer.
Where ICF limits incoming traffic to the Internet, it does not affect outgoing traffic. This means that whatever data is sent by your computer is still vulnerable to viruses or other disruptions, where ICF is still enabled.
If you have multiple computers that share the same Internet connection via ICS, you can enable ICF for all computers. At the same time, you can enable ICF for the router or system directly connected to the Internet, not for each system.