Protect your PC with Windows Vista firewall

If you have a PC connected to the internet, it needs to be protected. Anti-virus software is a must but so too is a firewall. The purpose of a firewall is to filter all the internet data ­ – or traffic – ­ that travels to and from a computer. Some web traffic is desirable, such as information that is received when accessing a website, but the same cannot be said of other data.

Many spyware infections transmit information back to another computer, which can lead to privacy problems such as identity theft.

By monitoring the electronic ports used to transmit such data, it is possible to block its transmission and help keep you and your computer safe. In this Masterclass we’ll explain how to configure Windows Vista’s firewall for maximum protection and convenience.

Turn on the firewall
Firewalls are important for all computers that are connected to the internet. Even if a small home network uses a router with a built-in firewall, it is a good idea to ensure that software firewall protection is available on each machine as well.

In this way, should one computer become infected, the risk of a virus spreading to others is greatly reduced. Windows Vista includes a built-in firewall and the first thing to do is check that it is enabled.

Open the Control Panel via the Start menu and double-click the Windows Firewall icon. If the dialogue box that appears has a red bar on the right-hand side, it means that the firewall is disabled – ­ if this is the case, click the ‘Change settings’ link and select the ‘On (recommended)’ settings before clicking OK.

Once this has been done, the link labelled ‘Allow a program through Windows Firewall’ to the left of the dialogue box can be used to take control of some aspects of how the firewall operates.

Granting outside access
Specifically, the Control Panel makes it possible to allow a particular application’s internet data through the firewall, or to block all incoming connections. Generally, the firewall should be fairly unobtrusive. Should another computer attempt to connect to your machine, a pop-up will appear indicating that the connection has been blocked but providing the option to unblock it.

Before enabling unblocking any connection, it is important to know what it is. If the pop-up appears out of the blue, it may be suspicious. But if internet or network-related activities are being carried out, check the details to ensure that the message directly relates to the task in hand.

While this is useful for day-to-day firewall configuration, the basic firewall options afford control over only incoming connections. While rules and exceptions can be created for outbound traffic, the options are slightly limited. If outbound connections need to be controlled, or more advanced options are required, Windows Firewall must be set up in a different way.

Open the Control Panel via the Start menu and double-click the Administrative Tools icon followed by ‘Windows Firewall with Advanced Security’. The firewall console can also be accessed by clicking the Start button and typing wf.msc before pressing Enter.

Vista’s firewall permits and denies network traffic using rules and these comprise of a number of criteria: the port through which communication is taking place; whether the traffic is inbound or outbound; the program that generated the traffic; the destination or source IP address; and the network protocol that is being used.

Used in combination, these criteria can be used to build up a series of rules that ensure only trusted traffic is permitted to and from your computer. In Windows Firewall’s left-hand pane, click the section labelled Inbound Rules. The rules that are then listed in the right-hand pane are those that can be controlled using the standard firewall Control Panel applet.

For more advanced control over traffic, click the Outbound Rules label beneath this.