Microsoft says Defender is enough and I believed it, but is that really the case? Do you have third-party antivirus software installed on your system?
Microsoft says Defender is enough, and I believed it—but is that really the case? Do you have third-party antivirus software installed on your system? Microsoft has consistently claimed that the built-in Microsoft Defender (the antivirus in the Microsoft Security Center) on Windows 11 is sufficient, and that the vast majority of users don't need to install third-party antivirus software. Microsoft's official blog even provides a guide on "How to confirm Defender
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Microsoft says Defender is enough, and I believed it—but is that really the case? Do you have third-party antivirus software installed on your system? Microsoft has consistently claimed that the built
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Microsoft Says Defender Is Enough — I Believed It, But Is It Really? Does Your System Have Third-Party Antivirus Installed?
Microsoft has long claimed that the built-in Microsoft Defender (the antivirus in Microsoft Security Center) on Windows 11 is sufficient, and that the vast majority of users don't need to install third-party antivirus software. Microsoft's official blog even provides a detailed checklist on "how to confirm Defender is properly configured," and it's quite thorough.
My initial reaction was agreement — that's not untrue. Defender is indeed far stronger than it was a decade ago. Independent labs like AV-Test have given it a perfect 18/18 in recent years, which was unimaginable back then. In those days, Microsoft Security Center scored below zero on AV-Test — the only mainstream vendor to ever achieve that result. Climbing from that level to today's 18/18 shows real engineering effort.
But whether it's "enough" depends on what you're comparing it to and what you're blocking.
Neil Rubenking, PCMag's veteran security reviewer who has covered antivirus software for over 30 years, recently wrote a rebuttal. He ran 24 phishing tests, pitting each antivirus against Chrome, Edge, and Firefox's built-in protections simultaneously. Here's what he found: Edge's built-in SmartScreen blocked an average of 75% of phishing sites, while third-party antivirus software averaged 95%, with nearly half achieving 100%. In other words, out of every 100 phishing sites, Defender's suite blocks roughly 75, and the remaining 25 land right in front of you.
That 20-Point Gap Is a Real Difference
More critically is browser coverage. Defender's SmartScreen only works in Edge and the retired IE. Users who switch to Chrome, Firefox, or Safari are essentially forfeiting that 20-point advantage Defender offers. Third-party antivirus software, on the other hand, typically supports at least four major browsers — Chrome, Edge, Firefox, and Safari are all covered.
Another detail is even more interesting. Microsoft's "it's enough" article includes a screenshot of "cross-device protection" with the caption "Add Defender to your iPhone, Android, Mac, and Windows devices" — looks thoughtful at first glance. Neil dug into the original file of that image and found the filename read "MSFT Windows Microsoft 365 consumer application screen." That screenshot came from the "Defender for Individuals" interface in Microsoft 365 Personal — two things with similar names but entirely different products. Using a Microsoft 365 screenshot to pass off as Defender functionality in an official Microsoft article is either negligence or deliberate obfuscation.
Hong Kong's Consumer Council released test results in June that are even more direct and interesting by comparison. Defender scored 3.5 points due to severe false positives, ranking last among 16 Windows antivirus products. For phishing protection, Defender scored just 1 point because it doesn't support Chrome at all. When faced with ransomware attacks, Defender also failed to activate its relevant protection features, managing only 2 points. Bitdefender Free and Kaspersky Free both scored a perfect 5, outperforming many paid products.
To say Defender is completely useless wouldn't be fair either. Microsoft's own SmartScreen, Defender real-time protection, and Windows Firewall are genuinely sufficient against conventional viruses and malware. If you only use Edge, keep your system updated, and are cautious about downloads, Defender won't let you down. It's certainly better than running bare.
But "good enough" and "secure enough" are two different things. A free solution blocking 75% of phishing sites is already decent — the problem is that it defaults to giving up the other 25% of protection, and that 25% becomes completely ineffective in cross-browser scenarios. Microsoft saying Defender is sufficient reads more like a description of what saves them money and effort, rather than the best advice for users.
My Own Setup (Free)
Microsoft Defender + Microsoft PC Manager. Most users probably no longer have the habit of paying for antivirus software anyway. Defender + Microsoft PC Manager — that combo is enough. Defender serves as the underlying safety net for viruses and malware; Microsoft PC Manager layers on top to fill in what Defender lacks — junk cleanup, pop-up blocking, and startup item management, features Chinese users are accustomed to. Both are official Microsoft products and completely free, with no third-party ads, no bundled流氓软件, no impact on boot speed, and minimal system overhead.
I've always advised friends around me to stop installing those "XX Security Guard" suites — that approach carries heavy costs when things go wrong: the system slows down, pop-up ads run rampant, and you end up with a bunch of rogue software installed out of nowhere. Microsoft's own Defender + Microsoft PC Manager combo handles all of this — no money spent, no third parties, and pop-ups fully eliminated.
In 2026, does your computer still have antivirus software installed? Drop a comment and let's discuss.
Written by our editorial team; tools listed here are tested or verified against public sources. Links point to official sites or GitHub repos for reference only — no paid placements.
