You turn on your computer, and it doesn't look quite right. Maybe your icons have changed, or the background picture is wrong. Some options are disabled. Even worse, you may not be able to boot your computer up at all. Guess what ? it's probably got a virus.

In today's online world, protecting your computer from all the nasty things online is vital. Viruses can cause obvious issues, as described above, but they can also run silently in the background, propagating themselves across your computer and transferring on to the computers of people you know. Mostly, you only know you have a virus when substantial damage has already been done.

Some common signs of a virus include:

• Programs working erratically
• Computer locks up
• Greyed out options
• The browser home page has changed
• Icons have changed
• Difficulties starting up the computer

There is a solution! Antivirus software is readily available, and the good ones are very efficient at dealing with viruses in all their many and varied mutations. Basically, if you're online, you need this type of software.

So which one do you choose? For starters, be careful of using something free off the internet, particularly if it's one you've never heard of. Sometimes these programs are a way of implanting more viruses on your computer. Some of the better known brands give you the option of doing a free scan online, which is useful, but not a long term solution.

It's really important to choose well-known antivirus software. Ask friends, or someone computer savvy, for their recommendations. It may be worth visiting a computer store and buying it there, rather than online ? after all, if they've gone to the trouble of stocking it, it's most likely an established and trusted product.

There are plenty of good brands available, far too numerous to list here, but some of the best known are from McAfee, Norton and Trend. Check out the support available to you ? can you contact someone if you have trouble installing the software?

Most importantly, make sure there's an easy way to update the software on a regular basis (preferably as part of the purchase cost!). For example, my antivirus software pops up a little box every time an upgrade is available. I click okay, and it's automatically downloaded to my computer. Viruses change and develop at an alarming rate, so it's vital to keep your antivirus software up to date.

Finally, the all-important backup! The word "backup" tends to produce the same glassy eyed response as the word "budget", but it really is an essential part of being online. Regularly backup your important files to CD or DVD. If you're a business user, an automated and frequent backup process is vital. Once a virus has destroyed your computer, it's too late.

Being online is wonderful, but don't let it become a nightmare. Antivirus software will play a vital role in keeping your online experience a positive one.

Copyright Felicity Walker 2005

Keeping her computer running smoothly is a priority for the author! To find out more, check out http://www.antiviruszoneonline.com for more information.