Malware, hackers, spam, identity thieves and more – which antivirus package should you invest in to prevent them playing havoc with your life? We test 10 of the best antivirus apps available

Antivirus isn't something you can get away without any more, and if you think you can't be infected, chances are there's a virus writer somewhere ready and willing to prove you wrong. You probably won't even know about it when it happens.

In the old days, malware tended to make a big song and dance about its presence, but the rules have changed. Now written with an eye towards online crime and cold hard cash, the average virus has learned to stay low and spread via almost any vector. The wrong website. A lost USB stick. A Facebook message.

You never know where they could strike, and even if you're up to speed on what they're doing now, sooner or later they'll find a new trick.

For these antivirus reviews, we've taken 10 of the best programs around and put them through their paces, not just to see how good they are at stomping viruses, but how much of your valuable resources they soak up.

We've all banished an antivirus tool for slowing things down or getting too obnoxious at some point – a modern tool should be expected to keep quiet until it has something important to say, and definitely not get in the way of the applications you're using or the games you want to play.

Finally, while most of these versions are available as suites, it's primarily their antivirus capabilities that we're looking at here. Each offers multiple versions at different price points, typically a pure antivirus tool and an Internet Security Suite edition that bolts on a firewall and often parental controls.

There's frequently a third edition too, focusing on features like backup and data security. The core engines are always the same, however, so don't feel you're missing out on anything if you don't need them.

Microsoft Security Essentials
Price: Free (Unlimited PCs)
Info: www.microsoft.com

You need antivirus, but do you need to pay for antivirus? There are plenty of free tools out there to choose from, including variants of many packages reviewed here (although we're looking at the commercial editions in the interests of fairness, the actual scanning engines are usually similar, if not identical), but Microsoft's is one of the few that's entirely free.

There are no upgrades on offer, no souped-up edition to try and upsell you to, and no irritating pop-ups to remind you that it's there. This makes it something of a stripped-down package – there's no firewall, not many options, no web filtering and no gaming mode.

It has all the basics though, including scheduled scans and real-time threat detection, the ability to mark certain files as safe and automatic scanning of all files you download from the internet.

On our test PC, it was by far the slowest antivirus package, taking 25 minutes for its first scan and 12 on a subsequent run, but clawed some time back when it came to reboots, barely affecting how long it took Windows to start up in the morning. It also had one of the lowest CPU utilisation scores on test, making it a good one to have running in the background.

As far as actual scanning goes, we had no complaints. Like most of the tools on test, it was a clean sweep, picking up all the malware on the PC and not falling for any of the false positives. It may be a free tool, but Microsoft has a vested interest in keeping Windows virus-free.

If all you want is a scanner and not any fancy features, it's more than up to the job of sitting in the background and protecting your PC, out of sight and out of mind.

Rating: 4/5