"Windows Firewall" refers to the built in client firewall utility that ships with the Windows operating system. (It was previously named the Internet Connection Firewall.) By default, all Windows operating systems since Windows XP and Windows Server 2003 have shipped with this client.

Windows Firewall Logo

"Windows Firewall" refers to the built in client firewall utility that ships with the Windows operating system. (It was previously named the Internet Connection Firewall.) By default, all Windows operating systems since Windows XP and Windows Server 2003 have shipped with this client.