Is Windows Defender Good Enough to Protect Your PC by Itself?

I mostly write reviews of VPNs, articles and features about VPNs, and responses to emails (of varying degrees of hostility) from or about VPN services. In nearly all of these contexts, I've tried to explain that VPNs (although excellent for securing your internet traffic) don't replace password managers, antivirus suites, or the use of two-factor authentication (2FA). But recently a reader asked me if I was implying that the security software from Microsoft was somehow lacking. That's a question worth considering.

Here's what our intrepid reader sent me. Note that this excerpt has been edited for brevity and to remove personal information.

The short answer is that the bundled security solution from Microsoft is pretty good at most things. But the longer answer is that it could do better—and you can still do better with third-party antivirus.

Is Windows Defender Any Good?

For those who are unaware, Microsoft Security Essentials was antivirus software included by Microsoft with Windows starting in 2009, until it was supplanted by Microsoft Windows Defender Security Center. With this software, Microsoft ensured that customers would have some kind of protection from the moment they first booted up their computer. It costs them nothing and doesn't require them to take any action.

When Microsoft's security offering first went under the microscope, it didn't impress. But it improved over time, so much so that it started to snag top scores from independent lab assessments. In his review, my colleague Neil Rubenking found that Microsoft's offering did an excellent job detecting and preventing malicious software.

Now, Defender hasn't totally stolen the spotlight away from the McAfees and the Bitdefenders of the world. You could chalk that up to decades of name recognition for competitors, but testing has revealed some notable shortcomings in Windows Defender. Rubenking found that the SmartScreen filter in Edge blocked just 68 percent of phishing sites, for example. That's particularly bad compared to the 89 and 90 percent blocked by Firefox and Chrome. In those tests, Kaspersky and McAfee blocked 100 percent of the phishing sites.

That's especially disappointing because phishing attacks can do a lot of damage to victims, and they don't require a lot of technical sophistication on the part of attackers. A phishing site tricks people into voluntarily handing over personal information—like credit card numbers—by impersonating a legitimate website. For more on this particular threat, you can read our story on how to avoid phishing attacks.

Windows Defender also doesn't cover the same breadth of products that third-party security companies do. The company that sells you antivirus software can also provide backup protection, a password manager, a VPN, parental control, and more besides, often rolled up in a security suite. 

A Matter of Perspective

I'm always glad when I get a reader question that I can answer definitively. I'm even happier when I can point to the work of some like my colleague Neil Rubenking, to back me up. But there was a point that I needed to take from this reader's question as well.

I realized that even when I tangentially recommend security products, I should strive to make the recommendations as accessible as possible. Windows Defender is a great example. It's something most people already have, works well, and doesn't require consumers to pay anything (beyond the cost of Windows, at least).

This is especially important because, to my mind, the two biggest obstacles preventing people from adopting good security practices in their lives are money and effort. Security software is not fun to buy and only a little fun to use. It's also expensive! These days, we're expected to pay subscriptions for the videos we watch, the games we play, and now security software. We're rapidly approaching a future where security and especially privacy area luxury afforded to the people that can pay extra.

It shouldn't have to be that way, and it doesn't have to be. High-quality free security products do exist, and Windows Defender is a good way to keep you and your computer safe. It is, however, not the best. For that, we recommend Bitdefender Antivirus Plus, Kaspersky Anti-Virus, and Webroot SecureAnywhere AntiVirus, among others. If you can afford them, these options will provide far more protection.