Always be careful to check any software you put on your computer is suitable and compatible with your existing setup. No liability can be accepted for any individual problems caused by acting upon the information given.

• SUPERAntiSpyware
"Remove all the spyware, not just the easy ones". This is the claim of SUPERAntiSpyware and from our experience with the program, it has not broken its promise. Adware, spyware, keyloggers, worms, and various other threats are identified and easily dealt with. You are able to schedule quick or more complete scans (daily or weekly), and real-time blocking ensures no rogue applications are installed in the first place. When used in conjunction with an anti-virus program, you will catch most, if not all, Internet nasties.

• Avira AntiVir Personal Edition
This version of Avira AntiVir is one of the best freeware anti-virus programs we've seen and offers effective protection against almost all computer viruses on the stand alone PC. This version detects over 50,000 different types of virus (rootkits, macros, trojans, etc.), and can identify and repair these quickly. AntiVir is made in Germany and is freely available to people using it non-commercially. They also provide free and regular updates.

• PC Tools AntiVirus Free Edition
The free edition of PC Tools AntiVirus is a user-friendly, feature-rich and highly capable antivirus program. Once activated, it guards your PC and begins looking for threats, such as trojans, worms, etc. You can also run a full system scan whenever you feel the need. Any viruses on your system will then be quarantined, disinfected or removed at the click of a button. Regular and free virus pattern updates are included so your system will be able to deal with the latest threats.

• Spyware Blaster
Are you wary about spyware? You needn't be if you install SpywareBlaster. Unlike similar programs that scan, detect and then clean your computer of any programs attempting to monitor your actions, SpywareBlaster takes a different route and prevents them from being installed in the first place. Nobody has to put up with spyware thanks to this clever little program.

• CoviroSoft AntiVirus
A free and effective anti-virus program, providing protection against a wide range of threats, including spyware, Trojan horses, keylogging tools, rootkits and of course, general viruses. CoviroSoft updates its threat database on a daily basis to constantly keep you protected. The software features a user-friendly interface with plenty of scanning options.

• Avast Free Antivirus
A reliable free anti-virus program for non-commercial (home) use. Avast is excellent at detecting and dealing with harmful viruses. The program provides a simple interface, e-mail mailbox scanner and resident protection shield. It also provides P2P (peer to peer) program and instant messenger shields. Free, automatic updates are provided as and when new virus threats are discovered.

Simple Ways To Protect Your Computer
The software your computer operates on already has some in-built protection; crackers and fraudsters often try to break through this software to exploit weaknesses and Microsoft is permanently upgrading its software to prevent them in a cat and mouse game.

Updates are available from Microsoft's dedicated website, but it's easier to set your computer to download them automatically. Just go to Control Panel and click the 'System' icon, then go to the Automatic Updates section where you can toggle the latter on or off.

Users of Apple Macs (and Linux) have slightly less to worry about in terms of viruses, as there aren't so many floating about for them...yet. Recent reports have seen more and more cyber criminals turning to the Mac platform, and as more people are using Macs than ever, this trend is likely to continue. Thus, it's now recommended that Mac users grab anti-virus software too.

If you're looking for a piece of software, find out who makes it first and then go to their site to get it. For smaller free/shareware programs, try using big sites like cnet's Download.com rather than just getting them from anywhere that shows up.

Free Anti-Virus Software
Launched earlier this year, Microsoft's security essentials package has gone from strength to strength since coming out of beta testing. The package is completely free to users of 'genuine Windows machines' - ie it'll verify your copy - and three versions are available, for XP, Vista, and Windows 7.

The free anti-virus software of choice for techies, Antivir's won many tech publications' free antivirus round-ups by providing both the most thorough software protection and the fastest. Yet the reason it doesn't top our list is that it's slightly less user-friendly than the Microsoft offering, with some of the settings requiring some technical knowledge to get right. Yet if you've the knowhow, it'll do everything you want it to.

AVG has a long history, and has been through loads of modifications to provide a better service on its way to the current version, AVG 9. It's protection is reasonably thorough, though it doesn't offer any real tech support.

Cloud-based anti-virus tools
Panda's paid-for software comes highly rated, and this totally free, no nag-screen online antivirus product clearly draws on the same expertise. In fact, in some tests, Cloud Antivirus detected even more threats than the top-performing Antivir software above.

Mac Anti-Virus software
As viruses are a relatively new worry for Mac owners, there are far fewer free programs available.

Offering simple bloat-free scanning in real time, this PC Tools offering covers all the basics quite well, and doesn't hog system resources too much either. Whilst it lacks the scope of paid-for programs from the usual suspects, it nonetheless offers a range of scanning options, and will auto-update itself whenever necessary.

However, it's worth noting it only looks for viruses and malware specific to the Mac platform; PC viruses will slip by undetected, which won't be a problem for you, but could cause trouble for PC-owning friends should you unwittingly email some malware to them.

Borne of the open source virus checker ClamAV, ClamXAV adds a user interface for Mac OSX, to make it accessible to people that don't think in code. Whilst technically it's free, donations towards the upkeep of its website will be gratefully received. In use, it's a tad more techie than iAnti-Virus, but it's great if you want to scan files for Windows threats before sending them onwards.

Free Firewall software
Anti-virus isn't the only protection your computer needs. If you don't have a Firewall, you're leaving all your files and sensitive information vulnerable. Therefore its important to get one.

Agnitum's Outpost Free Edition offers the ideal combination of top protection and good user-friendliness. It's a totally free product so there are no nag screens to contend with, and it comes highly rated by numerous tech sites.

Publisher Tall Emu's Online Armour firewall has been proved very efficient in tests, even outperforming some big-name commercial equivalents. It's light on resources, and heavy on security, so well worth checking out.

It's totally free to use but you will need to register and activate the licence by e-mail within 30 days of installation. Whilst Comodo outperforms many similar offerings, it can be pretty intrusive, especially if you just want a firewall that does it's job no questions asked. Tech support is available via email, but not by phone.

Free Ad/Spyware software removal
Spyware removers work by comparing what's on your machine to a list of known offenders. As ever, the top anti-ad/spyware programs are commercial, but that doesn't necessarily mean you need to buy them. Try these first:

Boasting awards aplenty, EMSI Software's A-squared free edition lacks the background scanning facilities of its commercial big brother, Anti-Malware, yet still packs in almost all its most useful functions. It's user-friendly with daily auto-updates, and has received excellent user feedback.

Whilst the free version doesn't provide real-time protection or scheduled updates, Anti-Malware is still powerful enough to make a big difference, and as a lightweight program it's pretty quick too.

Ad Aware's great at detecting and removing malware, and this version works even faster than previous ones. On the downside though, most of its features are locked in the free version, meaning that if you make it your primary tool, you won't be fully protected.

Spybot's been going for a while, and while it has a pretty long list of features, it's always received mixed feedback. It's fairly processor-hungry, so if your machine's already quite slow it'll be an unwelcome addition.

Free Anti-spam Software
Mailwasher. Rather than filtering through all your emails itself, Mailwasher works by allowing you to preview emails whilst they're on the server, so any nasty ones can be deleted before they make it to your machine.

Spamihilator. Also free, Spamihilator runs in the background and claims to recognise 98% of spam which it moves to a recycle bin. You can teach its filter what to look out for, and thus tune it to your needs. Hasn't been updated in a while though.

Free Back Up Software
What to back up? - A good way to think about it is if your PC shut down tomorrow and didn't switch back on again what files would you miss most? These are the ones you should be backing up as a minimum.

This is a growing sector, and thus as companies compete to gather custom, there's loads of free space up for grabs. US site Adrive offers a mammoth 50GB free, making it the leader in terms of allowance. Others include Windows Live Skydrive (25GB), and Humyo* (10GB).