A firewall is a software application, located at a network gateway server, which scrutinizes over traffic passing though it, and allows or denies passage based on a security policy.

The basic function of a Windows Firewall Security System is to maintain the traffic flow between computer networks of different levels. Its job can easily be compared to a passive fire protection (PFP) item with fire doors in building construction. As PFP is used to delay fire spread of fire to adjacent structures, firewall within network is used to prevent intrusion to the private network.

A firewall system requires proper configuration. Standard security practices define a ‘default deny’ firewall ruleset in which only explicitly allowed network connections are allowed. However, this is a kind of configuration which requires deep understanding of the network applications. There are several businesses which lack in this and follow a ‘default allow’ ruleset which allows smooth traffic flow unless it is blocked due to some specific reasons.

Operating systems such as Windows XP comes with Internet Connection Firewall. The user requires turning it on to use it.

Given below are the steps to active firewall security system:

• Go to ‘Start’ menu and click on ‘Control Panel.’
• Click on ‘Network and Internet Connections’.
• Click ‘Set up or Change Your Home or Small Office Network’.
• Follow the steps in the ‘Network Setup Wizard to turn on the Internet Connection Firewall’.

On selecting a configuration in the wizard that indicates direct connection of your computer to the Internet, the Internet Connection Firewall is turned on. Microsoft keeps on improvising its operating system for protection against Internet threats. Windows Firewall is an example of improved firewall protection. It was first released bundled with Microsoft Windows XP Service Pack 2.
Windows Firewall offers protection by blocking communications that can be a dangerous application attempting to find a way to connect to your computer. It will allow connections from home networks and block the efforts from people on the Web to connect to your computer.