Make sure you get a high quality anti-virus program, of which there are many available, some better than others. Do some intensive research on the net, or ask a question in various online forums, or even try Yahoo Answers. Go to your local magazine rack, check in the computer magazines for review articles or even look in the classified section to help you find the one which seems to do what you require.

See if it emphasises the removal of Trojan viruses, which is just another name for spyware.

Once you've got the right anti-virus software, make sure it's always running in the background whenever you are on the internet. It should be continually scanning incoming email messages, which are the main source of spyware, plus any software programs you are running, especially if they are ones which you have downloaded. If you have the original CDs of software programs, you should be pretty safe with those.

Once you have your antivirus programs, keep them updated with the latest versions. New viruses are coming out all the time and you need an antivirus system that can keep up. A lot of professional anti spyware programs will have an annual subscription, and will keep you alerted of any updates. Make sure you take advantage of these alerts, and always have the latest version. Some of the better programs will let you schedule these updates or a full system scan of your hard drive for off peak hours, such as the early hours of the morning, when you are not likely to be using your computer.

A good idea is to also keep your computer up to date. From time to time operating systems will be susceptible to security violations or they may have addressed issues, which were not done on your old computer. I try and update mine every two years; in fact I've just bought my latest one. Make sure you check periodically to make sure you are still running the up to date versions of all your software.

Make regular backups of your data, even though it may seem a chore. Most people on the Windows operating system keep their documents in the “My documents” folder. If you do this, it becomes easy to make a backup of all of your important documents simply by copying that folder. Buy yourself an external hard drive, and keep your backups on there. If possible, never have this external hard drive connected while you are on the internet, that way you will always have some uncontaminated data.

Take extra care if you use floppy disks or USB drives on public computers at your school or an internet café. Public computers are well known for carrying viruses and are not properly protected.

Be especially wary of attachments in incoming emails. Every email attachment is potentially dangerous. Never open attachments in emails from people you don't know, however tempting it might be. Even be careful of attachments from people you do know, who may be unwittingly transferring a virus from their computer to yours. The most common computer viruses replicate themselves by transferring themselves from one infected computer to another.

Use plain text emails if you can. HTML email is certainly prettier and gives you more control over formatting, but it can also more easily carry computer viruses. If you always use text based email, it's only possible to get a virus is by opening an attachment.

Don't download freeware or shareware files programs from the net without checking the source. There are lots of downloads available from popular reputable sources like Download.com that scan the programs before they make them available for download. Just to be sure scan the program before you install it on your computer.

I stay away from any instant messaging software, however popular it may be. Remember the more popular a program, the more tempting it is for computer idiots to transfer the viruses they have created