If you're going to connect to the internet, you need to protect your computer, otherwise it's like leaving your front door wide open with a big ‘Robbers Welcome' doormat on your front step. You've probably heard all the terms – such as virus, hacker, firewall, spyware and a million more – but perhaps think that the anti-virus programme that came with the computer, or that your PC-savvy mate downloaded for you is enough to keep you safe, right? Wrong …

First of all, you need a firewall. This is your first line of defence, making it extremely difficult for any hacker or malicious programme to get through. Nothing is 100% impenetrable, however, and an anti-virus programme that will always be on the lookout for anything nasty that manages to find its way in is essential.

But there are things that manage to get onto your pc in the most unlikely of ways: it can be inadvertently added by you as you download music, screensavers or games onto your PC, or it can even be added by someone you know and trust, such as a suspicious spouse or your employer. This is Spyware and is a frightening breach of privacy which allows people or programmes to see what you're doing, what sites you look at and even log your keystrokes so that they can reproduce everything you type, such as passwords and credit card details.

The only way to truly guard against spyware is to have a dedicated programme that detects and removes it.

So, you have your firewall and your anti-virus programme in place; surely an anti-spyware programme is just money down the drain? Unfortunately not: this will fill the cracks left by your other security programmes, and although it will not make your computer completely impenetrable (unfortunately the people writing these programmes are extremely good at what they do) it will be the equivalent of locking all your doors and windows and having an alarm system armed before you leave your house – someone could still get in if they really wanted to, but they'd probably rather go next door, where they've rather invitingly left a downstairs window open.

People are now using their computers for a range of personal and business applications, the loss or infiltration of which could do them serious emotional and financial damage. Taking preventative measures to ensure your online security should be as natural as closing the door behind you when you go out, and there are affordable and easy to use programmes out there to help you do just that.