Your buying guide for antivirus software
Every day new malware attacks of various descriptions target Windows PCs. Some are scarier than others, but the WannaCry ransomware attack that hit huge organisations including the NHS earlier this year left many people more uncomfortable with their PC security than most. A second big ransomware attack - Petya - has just hit the headlines in late June. (Also see: What is ransomware and more details on Petya.)
It costs nothing to ensure your software is patched and up to date, and installing a decent antivirus package needn't cost you a penny either. So there's no excuse for not having antivirus software on your PC.
The good thing about installing a free product from one of the leading security companies is that they use the same 'engine' as their paid-for products.
You do get more if you buy an internet security suite, but what you get in the free version is stripped down package with a smaller feature set. Don't expect to get extras such as spam filtering, improved firewalls, parental controls, password managers and support for mobile devices, although some of this can be had for free.
The free offerings from Avast, AVG, Avira, Bitdefender and Panda all offer basic antivirus and anti-malware protection, giving you a good chance to keep your PC free of threats which could lose you data and take a lot of time to put right.
Since testing antivirus software with real malware requires a lot of time and effort, not to mention extremely specialist knowledge, we don't do this ourselves. Instead, we use the latest results from several well-respected independent test houses, including SE Labs, AV-test.org and AV Comparatives.
Is free antivirus really free?
Right now, however, AVG is not sharing any data with third parties. It merely reserves the right to do so.
Best is Bitdefender, which claims not to share information with anybody outside its own company or subsidiaries. We think this is as it should be with a security product, but second-best is the assumption not to share, with an opt-in, should you want to receive ‘relevant’ offers. This is what Avast and Avira do. Panda does the same as AVG, requiring you to specifically unsubscribe to avoid security-related emails.
Does free antivirus software work?
Antivirus software is designed to prevent damaging programs from infecting your PC and laptop. All the free products here do that, but not all are as effective as others. As a secondary task, though, the full paid-for products should reduce the amount of unwanted advertising and offers that get through to you, and they usually offer quite a few other features as we mentioned above.
But without further ado, here are reviews of the leading free AV programs – you really can get something for nothing.
Bitdefender Antivirus Free Edition
Bitdefender rightfully has an excellent reputation in the antivirus world. Its products are simple, robust and reliable - what more could you need?
While its full product suites can get expensive, its free version is a very good basic package.
In fact, AV-Test awarded it the unbeatable score of 6/6 for protection, performance and usability, successfully blocking all malware during its tests in the first two months of this year.
There were no false-positives, either, which is when safe files or programs are reported as being unsafe.
SE Labs’ tests (from January-March 2017) found it wasn’t infallible, but it was compromised only one time, leading to an overall protection rating of 99 percent.
Overall, Bitdefender is easy to use, is lightweight and – in general – offers good protection for your PCs.
Avast Free Antivirus
Unlike some firms, Avast doesn’t hide its free antivirus offering so you can’t find it. A big orange button on its homepage makes this version more obvious than its paid offerings, so it’s a good start.
As well as basic antivirus protection, it offers protection from unknown threats and a handy password manager so you can log into sites in your browser by remembering just one password.
You don’t get the browser extension that warns of fake sites (such as banks), nor a privacy shield or spam filtering. Those come with Avast’s Internet Security package, while Premier adds automatic software updating and a file shredder.
The good news is that Avast’s antivirus protection is solid. AV Test gave it a full 6/6 in its most recent tests, and the same for usability. It lost only half a point in the performance tests.
SE Labs currently rates it at 92 percent overall, the same as in its October-December tests.
Avast asks you to opt-in to receive relevant offers, which may persuade some over AVG's forced opt-in to sharing data. Overall, then Avast is one of the best free antivirus packages around.
Best free antivirus: Microsoft
Windows Defender is built into Windows 10 and Windows 8, so it’s arguably the easiest option for most people since it’s probably in operation already unless you’ve disabled it or installed another antivirus program.
Unlike in the past, when it merely paid lip-service to virus protection, the modern Security Essentials is a credible and reliable AV engine. OK, it’s not the very best out there, but it certainly does the job.
If your PC or laptop is running Windows 7, you can download Microsoft Security Essentials for free.
As the name suggests, it offers basic antivirus protection. The only difference between MSE and Windows Defender is that the latter offers better protection against rootkits and Bootkits.
SE Labs awarded MSE 94 percent overall in its Jan-March 2017 tests, up six percentage points from the October-December 2016 tests. It is therefore currently ahead of AVG Free (93 percent) and Avast (92 percent).
AV-Test gave it 5.5 out of 6 for protection, 5 for performance and 6 out of 6 for usability. Just remember that these results all change as the months go by.
There are better paid-for choices than Security Essentials, but if you’re running Windows 8 or 10 with Defender built in, all you need to do is check that it’s enabled.
AVG Free Antivirus 2017
SE Labs gave it an overall rating of 93 percent from its test in Jan-March 2017 (its most recent report), along with an AA award (the highest is AAA).
This is the same result as from its previous test at the end of 2016, but its rivals have pulled ahead and overtaken it.
AV-Test’s results from testing in January and February showed that its protection was roughly the industry average and awarded it 5 out of 6.
It was given a perfect score for usability, and as we’ve used AVG Free on our own PC for the past year, we can – anecdotally – agree that it runs transparently in the background and you don’t really notice it. And that’s exactly what you want from your antivirus.
AVG has a simple-to-understand dashboard so, if you do ever venture to it, it’s very clear whether it’s up to date and protecting your PC.
In addition to an AV engine, it also warns you of unsafe web links and can block unsafe email attachments.
Avira Free Antivirus
Avira has previously topped our list of the best free antivirus programs, and it’s still a very strong contender. We like that you can download the full program as well as just the 4MB launcher, giving you the option to start the installation and then leave it to download the rest. It’s not alone in this, but it’s the only one we know of which also lets you download the full thing.
The interface is well designed and easy to use, and the latest version includes a couple of new features in its SearchFree Toolbar: a website safety advisor and the option to block advertising companies from tracking you online.
At first sight, it appears Avira bundles a firewall with its product, but this turns out to be an integrated front-end to the Windows firewall.
File scans can be scheduled and by default there’s a quick scan set to repeat every 168 hours or, as we techies call it, weekly. We reckon a quick scan could run more frequently than this, though.
AV-Test gives Avira great scores. In its recent tests in January and February, it handed a 5.0 for protection and 5.5 out of 6 for performance.
SE Labs didn’t test Avira in its recent roundup, and AV Comparatives hasn't any recent results.
Ultimately, Avira does a good job – even when compared to paid-for Internet Security programs.