The virus threat is real: new exploits are being discovered every day. And you won’t realise you’ve been infected until one day you boot up Windows and discover that your files have been encrypted – and you’ll have to pay a steep ransom to get them back. Save yourself the heartache by installing one of these powerful antivirus tools. They’ll keep you safe from the latest threats, and they don’t cost a penny – so there’s simply no excuse for going unprotected.
How to choose the best free antivirus for you
Can I trust a free antivirus tool?
You certainly can. These free packages come from respected names in the security industry, and they use the same detection engines as their premium, paid-for offerings. Their performance is confirmed in tests by industry specialists AV-Test.org. The publishers hope that you’ll be so happy with their software that you’ll upgrade to one of their paid-for security suites; typically these have a much richer set of features, as we detail in our reviews below. But you’re under no obligation – you can stick with these free editions for as long as you like.
What features do I need?
All of the free antivirus packages listed below do the basic job of spotting malware and preventing it from running on your PC. Additional security functions may be useful: for example, a tool might warn you if you’re visiting a website that’s known for stealing passwords, or dropping “Trojan Horse” programs onto your PC. A secure browser lets you access internet banking and shopping sites, safe in the knowledge that no one’s spying on you through your web browser. A firewall blocks connections to your PC from unknown sources. Often these features are only available in paid-for suites, but different publishers make different choices about what you can get for free.
Won’t antivirus software slow my computer down?
This was a real problem twenty years ago, but since then the industry has developed highly efficient techniques for spotting malicious behaviour while otherwise staying out of the way. The hardware has evolved too – for example, dual-core and quad-core processors mean your antivirus scanner can run concurrently with other applications, with no slowdown. In short, there’s no need to worry about performance: no matter which antivirus software you choose, your PC should feel remain slick and responsive.
Can’t I rely on Windows Defender?
Windows’ built-in antivirus tool is better than nothing, but it regularly places near the bottom of the table in detection tests. That’s probably because virus makers know that everyone has it, so they focus on exploits that Windows Defender misses. Since the Defender database is regularly updated, it will protect you against older viruses, but a third-party virus scanner is more likely to block the latest malware.
The best free antivirus for Windows
1. Bitdefender Antivirus Free: The best for silent, straightforward protection
If you like to keep things simple, Bitdefender’s free antivirus scanner will suit you perfectly. It focuses solely on spotting and blocking viruses, with no snazzy add-ons or extra features. And that’s a job it does brilliantly: in AV-Test’s last round of tests, the Bitdefender engine achieved a perfect score, blocking 100% of known “in-the-wild” exploits, plus 100% of never-before-seen “zero day” attacks
Bitdefender Antivirus Free isn’t intrusive either. It has almost no impact on your system performance, and doesn’t pester you unless a virus is found: by default it pops up occasional adverts for the full Bitdefender suite, but you can easily turn these off in the program’s settings.
If you’re the sort who likes to tinker with lots of settings, Bitdefender might not be the right choice, as there’s almost nothing to configure. You can however right-click on any file or folder in Windows Explorer and select the Bitdefender contextual menu option to trigger an immediate scan.
Download Bitdefender Antivirus Free now
Why is it worth upgrading to the paid-for suite?
![Image of Bitdefender Internet Security 2017 - 3 PCs, 1 Year [Download Licence Key Only] Sent by email](http://images-eu.ssl-images-amazon.com/images/I/51G2z5oPXXL._SL160_.jpg "Image of Bitdefender Internet Security 2017 - 3 PCs, 1 Year [Download Licence Key Only] Sent by email")
The full Bitdefender Internet Security product is much more extensive, including web browser protection, a password manager and specific technologies aimed at intercepting ransomware and phishing attacks. It also features a vulnerability scanner and a Wi-Fi security advisor, to alert you if your applications or network might be unsafe.
System requirements – Windows 7 SP1 or later, 2GB of hard drive space, 1.5GB RAM
2. AVG AntiVirus Free: An effective tool that includes web and email protection
Like all antivirus tools, AVG AntiVirus Free keeps an eye out for suspicious activity, but it also scans for dodgy browser add-ons and email attachments. We can’t fault its efficacy: AV-Test’s most recent report gave AVG a perfect 100% score against both known and zero-day threats.
The software will appeal to techie types who like to tweak their settings - there’s a huge range of options, allowing you to customise AVG’s detection techniques, decide how alerts should behave, and specify what the software should do when different types of threat are found.
The catch with AVG is that the free product is a bit pushy with the upsell. After installing it, you’ll see occasional pop-ups encouraging you to invest in other AVG products, and within the main interface there are numerous links and buttons that lead you to purchasing pages. Once you’re set up, though, you can disable pop-ups, leave AVG running in the background and forget about such irritations.
Download AVG Antivirus Free now
Why is it worth upgrading to the paid-for suite?
![Image of AVG Internet Security 2017 - 1 Year Unlimited Devices [Online Code]](http://images-eu.ssl-images-amazon.com/images/I/41ZNelsgvJL._SL160_.jpg "Image of AVG Internet Security 2017 - 1 Year Unlimited Devices [Online Code]")
The paid-for AVG Internet Security suite adds dedicated ransomware protection, a firewall to prevent hackers from getting into your system and an encryption module for ensuring your personal files stay private. The licence also allows you to install the software on an unlimited number of PCs and Android devices in your household.
3. Avast Free Antivirus: A wide range of features for those seeking all-round security
Alongside regular antivirus detection, Avast Free Antivirus includes an Updater that ensures you’re running the latest versions of your apps, a Wi-Fi inspector to warn if your network’s not secure, and a hardened web browser for online banking and shopping. If that’s not enough, there’s also a free password manager and a 30-day trial of Avast’s SecureLine VPN.
In AV-Test’s latest report, Avast’s virus-detection engine didn’t rank quite as highly as AVG’s or Bitdefender’s: it achieved a perfect score against known malware, but didn’t quite manage to intercept every “zero-day” attack, ending up with an average protection rating of 99.4% in that test. That’s still a very high level of protection though, confirming Avast as a capable antivirus package.
It must be said that the Avast interface is somewhat cluttered with links to modules that aren’t included in the free edition – but unlike AVG, it shows the icons for premium features in grey, so you can see at a glance what you’ve actually got. You get the same periodic pop-ups too, but these can be disabled in the Settings, making Avast a likeable package overall.
Download Avast Free Antivirus now
Why is it worth upgrading to the paid-for suite?
Avast Pro Antivirus adds web protection features that warn when you’re visiting a potentially dodgy site, and a sandbox to let you try out applications in a safe environment where they can’t affect your PC. The premium Avast Internet Security suite additionally includes a dedicated firewall, a spam filter and a module that protects specific folders against ransomware.
4. Avira Free Antivirus: A lightweight but highly configurable antivirus tool
Avira offers plenty of buttons and settings to play with, so if you like to specify exactly how your antivirus tool should behave, it’s a strong contender. It’s light on features, though; although the interface includes firewall options, this is actually just a front-end to the standard Windows Firewall.
If you want something more sophisticated, Avira also offers a complete Free Security Suite, which includes web protection, a password manager and a software updater. If you choose this edition, however, you’ll have to put up with a few in-interface adverts and upgrade popups.
As with Avast, AV-Test found that Avira fell just a whisker short of 100% protection: it averaged a 99.9% detection rate against prevalent malware, and 99.4% overall in the two-month-long zero-day test. While not perfect, those are strong scores - we’d have no hesitation in trusting Avira to protect our important data.
Download Avira Free Antivirus now
Why is it worth upgrading to the paid-for suite?
![Image of Avira Internet Security Suite 2017 - 1 Device / 1 Year [Online Code]](http://images-eu.ssl-images-amazon.com/images/I/71zwlwKQIOL._SL160_.png "Image of Avira Internet Security Suite 2017 - 1 Device / 1 Year [Online Code]")
Avira’s commercial Internet Security Suite includes anti-ransomware technology, a security checker for your home network and browser protection to warn you away from untrusted sites. While there’s no standalone firewall, the built-in firewall optimiser automatically adjusts your settings for improved protection.
5. Panda Free Antivirus: A stylish suite with a helpful USB rescue-disk creator
Panda Free Antivirus is a lightweight security tool with an attractive, Windows 10-style front-end. While not quite as minimal as Bitdefender, it offers a simple, basic set of capabilities, and it doesn’t nag you at all.
Protection consists of two main modules: real-time antivirus detection and website protection, to warn you if you’re visiting a site that’s known to be dodgy. Pay attention while installing, though, as by default it switches your default search provider to Panda Safe Web, which might be a step too far. There’s also a built-in tool for creating a bootable USB rescue disk, to detect and remove even malware that’s sunk its claws deep into Windows.
There’s not much to configure, but you can tweak important settings such as how the software should respond when a threat is identified. The last time AV-Test put Panda’s antivirus engine to the test, a few samples slipped through the net, but with a 99.5% hit rate against zero-day malware, and 99.8% against prevalent infections, Panda is a very credible contender.
Download Panda Free Antivirus now
Why is it worth upgrading to the paid-for suite?
Panda Antivirus Pro includes ransomware protection and a Wi-Fi scanner to warn you if your network’s insecure. It also includes parental controls, to keep your kids away from inappropriate content – and it runs on Android as well as Windows.