Using a firewall is very important when you use broadband or Wi-Fi.

This is because a fast, permanent internet connection makes you more vulnerable to hackers and rogue software like spyware.

Unless you want the hackers of the world snooping round your hard drive it's important to keep your connection secure.

Broadband security

With broadband, you are connected to the internet all the time your computer is switched on.

A firewall protects you from malicious internet activity by monitoring all the traffic which enters and leaves your computer and watches for anything unusual.

Perhaps the best known firewall is Zone Alarm which is free for home users and very easy to use

Every time a program on your computer tries to access the internet, your firewall detects the request, stops the program in its tracks and asks you if it's ok for this program to get access to the outside world.

In practice, a few programs like Internet Explorer, Windows Media Player and Outlook will want to access the internet all the time and once you've said that's ok, you won't be asked again.

The other type of firewall you might come across is built into the Windows or Mac OSX operating system. These offer basic protection but are also the most likely to be undermined by a serious hacker.

You should consider an additional program to be better protected.