I’ve Tested Every Major Antivirus. Please Don’t Rely on Just Microsoft Defender

I’ve been testing antivirus software since the 1980s, and I consistently recommend securing all of your devices with a strong antivirus—yes, even a free one can do the job. In a recent post, Microsoft effectively slammed that advice as incorrect. The post stated that Microsoft Defender Antivirus, the one that’s built into Windows, is all the protection you need, backing that assertion with a thousand words of enthusiastic prose. So is Microsoft right? My answer is a resounding no, and I’ll explain why.

Microsoft Defender: A (Very) Brief History

Microsoft has attempted to provide PCs with antivirus software for ages, all the way back to Microsoft Anti-Virus for MS-DOS in 1993. Its Windows incarnation started life as Microsoft AntiSpyware in the Windows XP era. But, true to its name, this app only handled spyware, not viruses or other kinds of malware. Over the years, it has gone by more names than our vice president, including Windows Defender, Microsoft Security Essentials, and Microsoft Windows Defender Security Center. We call its current incarnation Microsoft Defender Antivirus.

As noted, the earliest version strictly handled spyware. Even when it expanded to cover all kinds of malware, it didn’t do a great job. In several independent lab tests years ago, it earned below-zero scores, something that has never happened with any third-party antivirus app. In AV-Test Institute tests, antivirus software can earn up to 18 points, and most reach or come close to that top score. About 10 years ago, Microsoft routinely scored 15 points or lower, but in the last few years, it has regularly reached a perfect 18 points. Scores with other labs have risen in a similar fashion.

Microsoft Claims Defender Is “Enough”

Microsoft has long maintained that scores from independent labs aren’t relevant to Defender, because its extensive telemetry enables it to effectively validate Defender’s effectiveness. The project manager for Defender once told me he was offered a team devoted strictly to raising scores, but he declined, saying he’d just use them to improve Defender. By observation, though, Defender currently boasts both internal validation and high scores by independent labs. The recent post doesn’t mention lab scores, but the scores do suggest an improvement.

Microsoft’s post points out that Defender actively safeguards every Windows PC right out of the box, with protection extending to “running files, unsafe links, untrusted apps, and unauthorized changes to personal data.” It goes on to celebrate specific security components such as the central antivirus, SmartScreen Filter protection against malicious and fraudulent websites, and authorization-based ransomware protection. It also provides a handy checklist to ensure your Defender instance is configured for maximum effectiveness.

This post concludes that Windows 11 is the most secure Windows version yet, a statement I don’t dispute. It notes that Defender is “usually sufficient” when combined with good habits, such as keeping Windows and all your apps up to date. I’m not so sure about that.

Why Defender Alone Isn’t Enough

The Microsoft post does admit that you might need a third-party antivirus “if you manage multiple devices.” This is 2026. Do you know anyone who doesn’t manage multiple devices? At the very least, you surely have a PC (or a Mac!) and a smartphone. Sorry, Defender won’t do a thing for that phone or Mac. Maybe you’re managing protection for a desktop and a laptop. Most third-party antivirus solutions include some degree of cross-device management, ranging from simply checking the status of all your devices to taking remote actions such as launching an antivirus scan or triggering an update. You don’t get that with Defender.

“Neil, you dolt!” you say. “Didn’t you look at the Microsoft post? Right at the top, the picture mentions adding protection to your other devices.” And yes, it says very clearly, “Send a link to add Defender to your iPhone, Android, Mac, and Windows devices.” What gives?

(Credit: Microsoft/PCMag)

The image in question does not in any way reflect Microsoft Defender, the software built into Windows. It’s a screenshot from Microsoft Defender for Individuals, a component of Microsoft 365. In fact, the very name of the image file online (minus extraneous punctuation) is “MSFT Windows Microsoft 365 consumer application screen…”

I don’t know whether using that pic was an oversight or deliberately chosen to muddy the waters. If the latter, well, it succeeded.

Phishing Protection: Limited to Edge

A malware coder needs the skills to write code that will, say, steal your personal information, while also evading notice by the antivirus and operating system. A phishing fraudster only has to fool you, the hapless user. Defender’s SmartScreen filter will steer you away from phishing websites and other fraud. But there’s a catch. This protection only works in Edge (and the defunct Internet Explorer). Third-party antivirus apps invariably support Chrome, Edge, Firefox, and Safari, at a minimum. Defender doesn’t do a thing for browsers other than Edge.

(Credit: Microsoft/PCMag)

It gets worse. When I test phishing protection, I challenge the antivirus program alongside the built-in protections in Chrome, Edge, and Firefox. In the last two dozen tests, Edge averaged 75% detection of verified phishing pages. The third-party apps under test averaged 95%, and almost half reached 100% detection.

No Extra Security Features Included

Admittedly, Defender is free, so you can’t really expect security bonuses beyond basic antivirus. Or can you? Other free antivirus apps go well beyond the basics. Some of the many bonuses you’ll find in our favorite free antivirus apps are: active defense against trackers in the browser; a bootable rescue disk; dark web monitoring; secure file deletion; system tune-up; a vulnerability scan for missing security patches; and more. Yes, Microsoft’s post warns that “each added tool increases background activity and complexity,” but these aren’t added tools, just features of the antivirus.

If you’re willing to pay for your antivirus protection, you naturally get even better bonuses. These can include password management and VPN protection, as well as spam filtering, remote management, webcam protection, and even elaborate device control systems that let you limit or ban removable drives.

Scam Protection: You’re on Your Own

Everyone is using AI these days, including crooks and scammers. Deepfake images and videos, emails that seem truly convincing…AI is an amazing boon to the dishonest. The major third-party security companies all recognize this trend. Norton has offered its Norton Genie scam detector app for years. McAfee Scam Protection checks emails, texts, and links as they arrive, warning you of those that reek of fakery. Bitdefender’s Scamio Pro app does the same. These tools have their own AI built in, meaning you can quiz them using natural language if there’s anything you don’t understand.

Windows does include Copilot, but Defender doesn’t tap into it for scam protection. If you’re relying on Defender, you’ll just have to keep your scam-senses on high alert.

Defender’s Interface Falls Short

You probably don’t look at your antivirus all that often. When you do, you expect it to offer a clear view of your security status and easy access to all its security features.

(Credit: Microsoft/AVG/Bitdefender/Emsisoft/Norton/Webroot)

The image above shows Defender along with five popular antivirus apps. And even if you misplaced your glasses, it’s really easy to pick Defender out of the pack. Where the others clearly structure their displays to present the most information and functionality, Defender leaves most of its display blank. You can see a few recent activity stats or launch a quick scan, but for anything else, you must scroll way down or dig into links. Yes, it’s a matter of aesthetics, but I think Defender’s user interface is dreadful.

Defender: Better Than Nothing, But Not Enough for Most Users

It’s undeniably true that if you don’t have any other antivirus installed, Windows Defender steps up and takes on your defense. And it’s equally true that Defender is better than nothing—quite a bit better. The last thing I’d do is encourage you to disable Defender (which, in any case, is really, really hard to do). If you let your commercial antivirus subscription lapse, or if you haven’t yet installed protection on a new PC, it’s good to know you’re not charging off into the internet stark naked.

But if you think I’m damning Defender with faint praise, you’re right. You can do so much better. Maybe your budget doesn’t stretch to paying for antivirus? Look at our Editors’ Choice selections for free antivirus, Avast One Basic, and AVG AntiVirus Free. When your finances are in better shape, you can get even more extensive protection from our commercial antivirus Editors’ Choice apps, Bitdefender Antivirus Plus and Norton AntiVirus Plus.

About Our Expert

Neil J. Rubenking

Principal Writer, Security

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Experience

When the IBM PC was new, I served as the president of the San Francisco PC User Group for three years. That’s how I met PCMag’s editorial team, who brought me on board in 1986. In the years since that fateful meeting, I’ve become PCMag’s expert on security, privacy, and identity protection, putting antivirus tools, security suites, and all kinds of security software through their paces.

Before my current security gig, I supplied PCMag readers with tips and solutions on using popular applications, operating systems, and programming languages in my “User to User” and “Ask Neil” columns, which began in 1990 and ran for almost 20 years. Along the way, I wrote more than 40 utility articles, as well as Delphi Programming for Dummies and six other books covering DOS, Windows, and programming. I also reviewed thousands of products of all kinds, ranging from early Sierra Online adventure games to AOL’s precursor Q-Link.

In the early 2000s, I turned my focus to security and the growing antivirus industry. After years of working with antivirus, I’m known throughout the security industry as an expert on evaluating antivirus tools. I serve as an advisory board member for the Anti-Malware Testing Standards Organization (AMTSO), an international nonprofit group dedicated to coordinating and improving testing of anti-malware solutions.

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