When you have a computer, its important to keep it secure.  In order to do this, there are 3 simple things you can do.

1. Install Anti-virus software.

2. Install a firewall.

3. Keep your windows and your Anti-virus software up to date by downloading the latest version off the internet regularly.

These three steps are described in more detail below.

Anti-virus software

This is one piece of software you simply can't go without.  You can either go to your local pc shop and buy a copy, or alternatively you can buy a copy online.  A good shop for buying things online in the UK and the US is www.ebuyer.com.  Some well known and respected anti-virus products are Norton Anti-virus and Mcafee Anti-virus.

If you really don't want to pay for some anti-virus software, there are companies which make free anti-virus software, which should suffice, although I haven't tried them out myself so I don't know what they are like.  One such example is AVG anti-virus which can be found here.

One important thing you must remember is you MUST keep your anti-virus up to date.  New viruses are being released all the time, and if you don't download the latest virus definition files every week your anti-virus software is useless.  Just so you know, virus definition files tell your anti-virus software exactly what each viruse looks like, so every time a new virus comes out, the anti-virus companies need to make a new virus definition file.

Firewalls

This is another important piece of software which not many people have, but should have.  A firewall is a bit like a bouncer at a night club, in that Firewalls inspect all the data travelling into your computer and deny access to any dodgy data.  This means that firewalls try to keep hackers and other malicious users out of your computer.  If you aren't bothered about firewalls, then you should be.  For example, if you don't download any updates for Windows Xp from the Microsoft website, then without a firewall you can get infected by the blaster virus which can infect your computer over the internet.  A firewall will keep the blaster virus from sending its malicious data to you preventing you from being infected.

The good news is that there are some good free firewalls out there.  Windows Xp itself has one build in, although you usually need to turn it on as its switched off by default.  Alternatively, you can download an excellent free firewall from either www.kerio.com or from www.zonealarm.com.

You can also test the effectiveness of your firewall for free by visiting the website here, and clicking the "Shields Up" link on the website.  I suggest you run the "Common Ports" test and if the test results come up as "Stealthed", then you have a firewall installed which seems to be working properly.  Please remember that while firewalls keep most malicious traffic out, they may not block all malicious traffic so you still need to have anti-virus software installed and download all the latest updates for windows.

If you have Windows Xp, you can either use one of the two firewalls listed above, or you can use the built in one.  To turn it on, please follow the following steps;

1. Click "start", then "My Network Places".
2. On the left of the screen, under "network tasks" click "view network connections".
3. Click the icon that corresponds to your internet connection with the right mouse button and choose properties. (Note, if you are unsure which connection is your internet connection, then you can simply turn on the firewall for all of the connections by repeating steps 3 - 6 for all the icons).
4. Click the advanced button, and then make sure the box which says "Protect my computer and network by limiting or preventing access to this computer from the internet" is ticked.
5. Once you've ticked the box, then click ok. 

Congratulations - your computer should now have a firewall running and be safe from malicious outsiders.

Windows Update

As you are probably aware, security flaws are being found in Windows all the time and need to be fixed.  This is easily done by visiting www.windowsupdate.com.

You then click "Scan for updates" and download any updates which appear in the critical updates section.  I recommend you do this every week and if not at least every month.

By following the advice above, your computer will be much better protected from malicious threats.