How to choose the best antivirus software

Antivirus software packages

How to choose the best antivirus software

by Adam Marshall

Protecting your PC or Mac from a virus is easy with internet security software - but deciding which package to install isn’t. We have expert advice on picking out the best antivirus suite, and tell you whether free antivirus is worth considering.

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The internet is full of threats, but that's no reason not to enjoy the best of the web - the key is keeping your Mac or PC properly protected with an internet security package. Viruses and malware can infect your computer in several ways, but the best antivirus software will give you peace of mind that your computer and personal data are safe.

Take a look at our antivirus software Best Buys to discover the models that Which? recommends.

Paid-for antivirus software

Most people keep their computer safe by buying a security suite, which will usually include antivirus, antispyware software, and a firewall. Your security package should cost from £30-£50, and usually includes a year’s subscription to software updates to keep it up-to-date with details about the latest threats.

The best security software suites come with extra features such as parental controls, maintenance and back-up and recovery tools that can help you restore your computer in the event of a disaster. Generally, they also have better customer and technical support than free internet security.

Most brands have options for just one device or, for more money, multi-user licences so you can install the same protection on two or more computers in your home.

Pros: Provides an all-round antivirus, antispyware and firewall solution accessed through a single interface. Individual components are automatically updated at the same time so you get protection against the latest threats.

Cons: They can be expensive – from £30-£50, and you’ll also face ongoing costs, usually in the form of an annual subscription in order to receive updates after the initial period of protection is over (usually a year). Some security suites can place a huge drain on system resources, too, potentially slowing down your computer’s operation.

Check out our pick of the best antivirus software. 

Free antivirus software

You may not need to buy security software. Depending on the type of computer you have, it may already come with certain security features installed on it.

Alternatively, you can download free antivirus tools from the internet that provide a good level of protection. And it’s possible to get most of the features supplied by paid-for internet security by using a combination of free antivirus downloads, though they won’t be packaged up neatly in one place and you can risk compatibility problems.

Pros: You can use your chosen antivirus, anti-spyware, anti-spam and firewall programs in tandem to completely protect your PC or Mac without spending a penny. And because they’re free, you can try out different packages before settling on the one for you.

Cons: They provide only a basic level of protection and lack the extra features of paid-for security software. You’ll have to keep each individual program updated to ensure you’re protected against the latest threats. Plus, free antivirus software is typically single-user, so you’ll need to download, install and manage a separate version if you have more than one computer.

Download a package to give you peace of mind with our best free antivirus software. 

Windows 8 security and Windows 10 security

The biggest shake-up in PC security for years came with Microsoft’s launch of Windows 8. Unlike previous versions, it came with lots of security features baked right into the operating system, and Which? found Windows 8 to be very secure in our tests.

We’ve yet to test out Windows 10 security in our test lab, but we expect it to include similar security provisions as Windows 8. One of the key changes for Windows 8 was the replacement of Microsoft Security Essentials with Windows Defender. Defender has been beefed up to include antivirus protection along with anti-spyware features. It runs in the background and notifies you when you need to take action.

Windows 8 and 10 users are further protected by a two-way firewall that monitors the information going back and forth to the internet. Other features include a SmartScreen filter to help protect against phishing scams, plus parental controls to monitor children’s activities online. Windows 8 and Windows 10 both include a Secure Boot option that prevents malware from gaining a foothold on your PC during start-up.

Pros: We found that Microsoft Windows 8 has strong built-in security and antivirus features, and we fully expect Windows 10 to continue this trend. Which? has found that this means you don’t need to use additional security software if you’re running Windows 8 – we’ll know soon if the same is true on Windows 10.

Cons: Because of the sheer amount of Windows users, Microsoft’s operating system is frequently made the target of hackers and creators of viruses. PC users with versions of Windows prior to Windows 8 should certainly seek to install separate security software.

Mac security software

Despite their reputation for being more secure than Windows PCs, Apple Mac computers are not immune from viruses and malware. With more Apple products being sold, the target audience for hackers is becoming more attractive. This makes it more likely that viruses will be designed specifically to attack Macs, so it makes sense to think about Mac security software.

Apple continues to boost security in each new version of the Mac OS X operating system. But Macs do not include antivirus or anti-spyware software, although they do have a built-in firewall to block attacks from malicious users online. There’s plenty of paid-for and free security software for the Mac to choose from.

Pros: Apple computers are generally less vulnerable than PCs, so you may decide that you don’t need to splash out on antivirus for Mac.

Cons: Perhaps due to Apple’s reputation for being less susceptible to malware, there aren’t a huge amount of security packages available – and those we have tested have on average scored worse than antivirus suites for Windows.

Get the best package for your Apple Mac - we’ve picked out the best antivirus software. 

Do I need two antivirus packages?

There's a long standing adage that using two antivirus products is a bad idea because they can cause glitches, with two programs trying to perform the same task. Limiting yourself to one internet security program also minimises the impact of AV software on the performance of your PC.

It’s not always a security power struggle, however. Some additional programs can prove invaluable if you’re after a second line of defence.

Pros: We've seen some security software that usefully bolster the malware fighting elements of your main antivirus package. Malwarebytes Anti-Malware, for example, is a standalone security tool that can be installed alongside your regular security software - and it has a brilliant track record for vanquishing virtual nasties. Plus, it's free.

Cons: It's true that having two full programs installed at the same time can seriously slow down your system. From time to time, they may both assume that the other package is scanning your system, leaving you vulnerable to malware that slips through the cracks. And if one Best Buy program is enough, why bother paying for two?

Removing old security software

Many anti-virus packages will automatically attempt to remove rival products. This process typically happens as part of the installation of a new security suite, though this isn't always the case.

If you need to manually remove an older package on Windows, click Control Panel (or search for this within the Start menu) then, under Programs, click Uninstall a program and locate the software you want to remove from the list. Select the program, and then hit Uninstall in the toolbar above.

But beware: if you uninstall your PC’s defences to install another but don't install another one immediately, you will be left unprotected.