Rob Freeman, Click's very own Mr Fixit, troubleshoots your PC problems and helps you get the most out of your computer.
In case you did not know, there were something like 40,000 new computer security threats created last year, targeted overwhelmingly at Windows users.
But as long as there have been viruses there have been companies who make their money by protecting computers from them.
This is very big business; $4bn (£2.97bn) was spent on virus protection last year. Given those figures I still find it amazing that so many people leave their computers open to attack from the various nasties out there on the internet, in fact some 50% of PCs do not have protection - even when there is a basic level of free protection available.
This week we are going to look at the options for free anti-virus software.
First up, from the Czech Republic, comes AVG (http://free.grisoft.com/doc/1). Previously it was only free for UK users but now everyone can download it.
There are reports of it bringing up excessive false positives, that is, telling you a file is a virus when it is not, and the interface is not what you would call pretty, but it is free.
From Romania comes BitDefender (www.bitdefender.com)- click on the downloads link to find the free products section.
BitDefender used to have versions for Palm and Windows CE devices, now the only alternative version left is for Linux.
Also from the Czech Republic comes Avast 4 Home (www.asw.cz) - click on Products and Select Free Software to find the download link.
It is available in a staggering 26 languages, but you will need to register it to get the updates.
Finally, a German newcomer, Avira (www.free-av.com), has appeared since the last time we looked at this topic.
Avira has versions for current Windows systems, as well as older ones like Windows 98. There is also a version for Linux as well.
It comes with a free UnErase program, with which you can try to rescue files which have been deleted.
Free protection is better than none at all, but do give some thought to the benefits you will get from upgrading to a pay version.
This includes faster protection from new threats because, in most cases, the virus definitions in free software will not be updated as often as pay versions.
Upgrades start from around £20 and I think that is a bargain.
Remember: there is always a reason that something is free, so have a look at the small print.
These products are only for personal use, and they come with either minimal support, or no support at all.
This can still be OK if you have confidence in the company which makes the software, and you know enough about your computer to handle any problems you might get with it.
However, in many cases, there are online forums which spring up around free software like this, which can help you troubleshoot.
If you want to investigate the different pieces of free anti-virus software that are out there you could do worse than check out places like download.com or Tucows - they have vast numbers of freeware and shareware programs, and the products are rated by users, which gives you an idea how good or bad they are.
The important point that you have to ask yourself why the software is free? And if you really take your security seriously you need to make sure your free software is as good as one of the paid for solutions.