Is Windows Defender Enough to Safeguard Your PC in 2021?

Windows Defender – or, as it’s now called, Defender Antivirus – is Microsoft’s built-in antivirus software, which comes pre-installed on all its PCs. Since it’s both free and conveniently set up and ready to go from day one, for many people this remains the sole or primary security measure they use on their computer.

But while Windows Defender has certainly improved significantly since it was first released in 2004, it’s far from a perfect antivirus solution. Among its drawbacks is its failure to update virus definitions on a regular basis meaning it can be prone to vulnerabilities. So, the question is, is Windows Defender enough?

In this article, we’ll take a look at the benefits and limitations of using Windows Defender, and whether it’s enough on its own to keep you safe.

Is Windows Defender Enough on Its Own?

Not really, but here’s the good news: the very latest version of Defender (i.e. Defender Antivirus 4.18) has progressed immensely from its frankly terrible previous iterations. Improvements over the past few years mean that it now offers real-time threat detection, a firewall, a cloud-based virus library to speed up scans without dragging down performance, and even parental controls – albeit limited to Microsoft browsers (so not Chrome, for example). When it comes to core malware-detection capabilities, it’s now on par with industry-leading free AV software.

The bad news is that there are still a ton of shortcomings you need to be aware of when you use Windows Defender:

• You really do need the very latest version

While the very latest version of Windows Defender (called Defender Antivirus 4.18) was granted a perfect score by the independent lab AV-Test for performance, protection, and usability in 2020, older versions perform very poorly indeed.

All of this means that the very latest version of Defender is great at detecting malware, but if your version is even a few years old, you may as well have no protection at all.

• It doesn’t protect you automatically on all internet browsers

You need to install all your internet security features on every single type of browser separately. This can really catch people out who presume that having Windows Defender pre-installed means that you’re protected against malware or viruses whenever and wherever you are online.

• It doesn’t update often enough

Microsoft doesn’t update either its virus database or its core software enough to really stay on top of all threats. Sure, if you’re using a version that has just been updated, you should be fine. But whereas most antivirus software make an effort to stay current all the time, Defender leaves things to the next update, so you may get caught out.

• It lacks extra features – There’s no VPN, password manager, payment protection, file shredder, or safe shopping browser extension to block phishing sites. Kaspersky Antivirus is chock full of features (even the free version).
• It only works on your PC – can only be used on a PC. That means you’ll need to get a separate AV anyway to cover all your other devices
• It’s not very intuitive to use –  it can be tricky and confusing to navigate.

Combine Defender with a Strong AV Software

The best way to handle the weaknesses of Windows Defender is to use it in conjunction with another antivirus software. In fact, Microsoft actually tells users they should do that. If you find you get a virus, Defender doesn’t try to help you fix the problem; it just informs you that you should have been using a secondary AV as a backup.

However, on the plus side, Defender has been deliberately set up so that it won’t clash with other AV programs or interfere with their operations. This means that using Windows Defender alongside another free antivirus isn’t only a sensible way to get rock-solid protection on all your devices, it’s also hassle-free.

Windows Defender vs Other Free Antivirus Programs

It’s worth bearing in mind that to get the full range of features from the best antivirus software, you will need to invest in the paid versions. That being said, there are some excellent free and low-cost options out there. Let’s see how they stack up against Windows Defender.

Windows Defender vs Kaspersky

KASPERSKY: Real-time threat detection: Yes. Firewall: No. Password Manager: Yes. Real-time security updates: Yes.

An excellent free program for malware detection on all your devices is Kaspersky, which combines high-quality antivirus scanning with system cleanup tools. You can run real-time scanning in the background without your device taking much of a hit. What’s more, there’s a password manager (limited to 15 logins), a dark web scanning feature, and even a reasonably good VPN – although it’s limited to 200MB per day. Windows Defender doesn’t offer any of these bells and whistles.

How does Kaspersky compare to the latest Windows Defender in Lab Tests?

Independent lab testing by AV-Test awarded both Kaspersky and Defender Antivirus 4.18 a perfect 6/6 for protection, performance and usability.

Both Kaspersky and Defender Antivirus 4.18 successfully blocked all zero-day threats and detected 100% of widespread and prevalent malware that had emerged in the previous 4 weeks. Neither of them falsely labeled any harmless websites as malicious during a system scan. However, Kaspersky mistakenly labeled one item of legitimate software as malware during a download, while Defender falsely labeled two.

Having Kaspersky running in the background slowed computer performance by a maximum of 13% while browsing the net or launching common applications; Defender slowed it by just 5%. Interested in trying out Kaspersky antivirus? Take a look at our full review here >

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Windows Defender vs AVG

AVG: Real-time threat detection: Yes. Firewall: Yes. Password Protection: No. Real-time security updates: Yes.

The free version of AVG is missing some great features of the paid version, such as protection against webcam hacking and ransomware, but it still has some excellent additions that go above and beyond Windows Defender. These include a file shredder, USB scanning (although you need to do this manually), and scan controls, which allow you to schedule scans or adjust their intensity to minimize the impact on your computer.

Plus, you can set up AVG in “passive mode” which means it will tick along quietly in the background while Windows Defender acts as your main AV, picking up any malware that slips through the net.

How does AVG compare to the Latest Windows Defender in Lab Tests?

Independent lab testing by AV-Test awarded AVG 6/6 for protection, 5.5 for performance, and 6/6 for usability. The latest Defender Antivirus 4.18 scored 6.6 in all categories.

Both AVG and Defender blocked 100% of zero-day threats and detected 100% of widespread and prevalent malware that had emerged in the previous 4 weeks. AVG outperformed Defender by not falsely labeling any harmless websites or software downloads as malicious during a system scan, while Defender falsely flagged two software downloads.

However, using AVG did slow browsing/launch of standard programs by up to 33% while the program was in use, and on one occasion blocked legitimate software from performing certain actions. Defender only saw a 5% dip in performance. Has AVG piqued your interest? You can read our complete review here >

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Windows Defender vs Avast

*The free version Avast has a major security flaw: it’s recently been found to be harvesting and selling user data to third parties. For that reason, we wouldn’t recommend choosing this free antivirus at this time.

AVAST: Real-time threat detection: Yes. Firewall: No. Password Manager: Yes. Real-time security updates: Yes.

The free version of Avast is easy to use, although you’ll want to pay close attention to your options during installation, as it will try to install its Safe Browser as your default browser and opt you in to data collection on your internet usage. There’s a built-in password manager, too, which is handy.

How Does Avast Compare to the Latest Windows Defender in Lab Tests?

Independent lab testing by AV-Test in 2020 awarded Avast 6/6 for protection, 5.5 for performance and 6/6 for usability. Windows Defender scored 6.6 on all fronts.

Like Defender, Avast also blocked 100% of zero-day threats and detected 100% of widespread and prevalent malware that had emerged in the previous 4 weeks. It didn’t falsely label any harmless websites or software downloads as malicious during a system scan, whereas Defender mislabelled two.

However, it did slow browsing of popular sites by up to 33% while the program was in use, compared to 5% when using Defender.

Conclusion: So How Good is Windows Defender Really?

Provided you’re using the up-to-date Defender Antivirus 4.18, Windows’ offering is pretty good. But it’s not good enough on its own. To get all the extra security features you might expect in 2021, you’ll need to supplement Windows Defender with another high-performing, free antivirus.

Not only will installing an AV that updates more regularly than Defender ensure that you catch any malware that slips through the net, but it also means you can take advantage of excellent additional tools like VPNs, password managers, and firewalls. It’s well worth making sure you choose one that works on all your devices, not just your PC, for complete protection.