Page last updated at 14:15 GMT, Friday, 12 December 2008

How to keep your computer secure

Computer user

Keeping your computer secure from nasties on the web is often overlooked, but taking a few simple steps can minimise the risks from viruses, Trojans, worms, spyware and all other forms of infections.

Prevention is the best way to protect a machine from being attacked by malicious software, also known as malware. Users can try and prevent malware infecting their computers by using a firewall.

But if a PC has already been infected by malware, the cause of the infection could be eliminated by using anti-virus or anti-spyware software.

So what is a "firewall" exactly? And what do we mean by "anti-virus"?


A firewall will try and prevent infection in the first place, and acts as a first line of defence against the web's more unpleasant elements.

It monitors inbound and outbound web traffic on a computer, searching and blocking behaviour consistent with malware.

Whichever operating system you use, check that your firewall is already switched on. This happens as standard with Windows Vista and later versions of Windows XP but not with Mac OS X.


Check if your machine's firewall is on by opening the control panel and selecting firewall settings. Then look at the check box to see if Microsoft's firewall is switched on or off.

That said, commercial alternatives can provide a more comprehensive level of protection.

There are many tried and tested third-party firewalls available. Some less-known but perfectly adequate pieces of software, are available as a free download.

Many of the free packages also have grown-up fully featured paid-for alternatives.

If you decide to plump for a third party firewall, you may need to switch the Microsoft firewall off. Often MS firewall will conflict with third party firewalls.


While a firewall is the first line of defence, it should also be used in conjunction with good anti-virus and anti-spyware software.

These pieces of software should hunt down and eliminate malicious software lurking on a machine. But make sure only one piece of anti-virus software is installed at a time.

If you purchase or download new anti-virus software, uninstall any previous protective software that may be running on your machine.

Like the firewall, running multiple anti-virus suites can cause software conflicts and create major computer performance issues.

There are also paid-for and free versions of anti-virus and anti-spyware software available.

Many of the free options have fewer and more basic features than the full price alternatives.

In addition, it is important to make sure that anti-virus software and the operating system is updated regularly.

New threats are being released onto the web all the time, so anti-virus and operating system updates are required to combat these threats.

For less experienced users, many of these updates can be performed automatically, by instructing both the operating system and anti-virus to auto-update.

Q&A: Stay safe online
17 Nov 08 |  Technology

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