The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →For most people using an up-to-date Windows 11 PC at home, Microsoft Defender Antivirus is a capable built-in starting point, so buying another antivirus is optional—not a basic requirement. A third-party suite may be worth paying for when it provides a specific feature, device coverage, or central management you need. Compare that value alongside independent test results, performance, usability, and the plan’s current terms.
What Microsoft Defender includes in Windows 11
Microsoft Defender Antivirus is included with Windows 11. Microsoft documents real-time, behavior-based, and heuristic protection, cloud-delivered threat intelligence, and automatic updates as part of its protection. It is distinct from the Microsoft Defender app and Microsoft Defender for Endpoint. Microsoft’s Windows 11 virus and threat protection overview describes the built-in protections.
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Windows Security also provides tools beyond antivirus scanning, including SmartScreen, tamper protection, optional blocking of potentially unwanted apps, and Controlled folder access. The latter can protect selected folders from untrusted apps; if it blocks software you trust, you may need to allow that app deliberately. Microsoft’s Windows Security support guide explains these options.
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What independent test results say—and what they do not
Recent lab results show that Defender can perform strongly, but each result applies to a particular product version, test period, configuration, and methodology. It is evidence for comparing products, not a guarantee that an antivirus will stop every attack on every PC.
#1 Best Overall
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| Product and test | Protection | Performance | Usability |
|---|---|---|---|
| Microsoft Defender Antivirus Consumer 4.18, Windows 11 Professional, May–June 2026 AV-TEST home-user evaluation | 6/6 | 5.5/6 | 6/6 |
| Microsoft Defender Antivirus Consumer 4.18, Windows 11 Professional, September–October 2025 AV-TEST evaluation | 6/6 | 6/6 | 6/6 |
| Bitdefender Total Security 27.0, Windows 11, September–October 2025 AV-TEST evaluation | 6/6 | 5.5/6 | 6/6 |
| ESET Security Ultimate 18.2, Windows 11, September–October 2025 AV-TEST evaluation | 6/6 | 6/6 | 6/6 |
AV-TEST’s May–June 2026 evaluation covered 16 home-user products on Windows 11 Professional, using default settings and current publicly available versions. In that test, Defender blocked 100% of the real-world zero-day samples in both May and June and 100% of the recent prevalent-malware reference set in both months. Those percentages describe only the samples and test period, not all threats. AV-TEST scores protection, performance, and usability out of six points each; its methodology awards a Top Product designation at 17.5 points or higher. See AV-TEST’s Windows home-user results and methodology.
AV-Comparatives’ 2025 consumer main-test series examined 19 Windows security products; 15 earned its Approved Windows Security Products certification. Its testing considered real-world internet threats, recent malicious programs, targeted attacks, slowdown, false alarms, and user experience. Its Top-Rated products were Avast, AVG, Bitdefender, ESET, G DATA, Kaspersky, and Norton. These awards reflect that test series, not a universal ranking for every person or configuration. Read AV-Comparatives’ consumer testing information.
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For its July–October 2025 Real-World Protection Test, AV-Comparatives used fully patched 64-bit Windows 11 systems and distinguishes outcomes that depend on a user’s decision from protected outcomes. The result graph provides the detailed comparisons; the tested-product list alone is not enough to infer a product’s protection percentage. View the test results and explanation.
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When Defender is likely the right choice
- You want a built-in option without another antivirus subscription.
- You use Windows 11 at home, keep Windows and applications updated, and are comfortable using Windows Security.
- You do not need a particular additional feature or a central console for multiple devices.
- You are willing to check that Defender’s real-time and cloud-delivered protection are enabled and that it is the active antivirus provider.
For cloud protection, Microsoft describes a service that can deliver fixes within minutes for qualifying Defender issues. That is not a promised response time for every threat or configuration. Microsoft explains how Defender cloud protection works.
Rank #3
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- ONGOING PROTECTION Download instantly & install protection for 5 PCs, Macs, iOS or Android devices in minutes!
- TOP-PERFORMING VPN Faster speeds, more server locations, and greater connection control to protect your privacy across all your devices, including Smart TVs.
- ADVANCED SCAM PROTECTION Help spot hidden scams online. With the built-in Genie AI assistant, you’ll never wonder if a message or email is suspicious again.
- REAL-TIME PROTECTION Advanced security protects against existing and emerging malware threats, including ransomware and viruses, and it won’t slow down your device performance.
- DARK WEB MONITORING Identity thieves can buy or sell your information on websites and forums. We search the dark web and notify you should your information be found.
When a third-party antivirus may be worth it
Consider another product when you can name what it adds for you—for example, a specific feature, management across multiple devices, or broader device coverage. Check the current plan details directly: the features included, supported devices, price, renewal terms, and regional availability can vary. The test results above cannot establish which current subscription offers the best value, and no current prices or bundles are established here.
Do not choose on detection scores alone. Compare protection with performance impact, false alarms, and usability, then weigh those results against the features and terms of the plan you would actually buy. AV-TEST and AV-Comparatives use different test methods, so read the date and scope of each result rather than treating scores from different evaluations as one head-to-head ranking.
Rank #4
- THREAT DETECTION – Stay one step ahead. Suspicious links, risky sites, viruses, and scams, caught automatically before they reach you.
- PERSONAL INFO PROTECTION – Keep your personal info safer. Identity monitoring watches for your exposed info and tells you what to do about it.
- SECURE CONNECTIONS – Just a few easy clicks, and we'll automatically protect your info on public Wi‑Fi, every time you connect.
- GUIDED ACTION – Know what matters and what to do next. Clear alerts and simple guidance make it easy to take action.
- MORE THAN ANTIVIRUS – Scam protection, identity monitoring, VPN, web protection, and antivirus work together to protect you, all in one place.
How to check which antivirus is active
- Open Windows Security.
- Select Virus & threat protection.
- Open Manage providers or Who’s protecting me? to see which antivirus provider is active. Microsoft’s interface wording may vary by Windows version. Microsoft’s guide to Virus & threat protection covers the page.
- If you rely on Defender, check that real-time protection and cloud-delivered protection are on. Use Windows Security’s quick, full, or offline scan options when you need to scan.
Microsoft says Defender Antivirus turns off automatically when a compatible third-party antivirus is installed and enabled, then turns back on after that product is uninstalled. Verify the active provider after installing or removing antivirus software rather than assuming the handoff worked as expected. Microsoft documents the provider handoff and security controls.
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Exclusions are not a routine way to improve antivirus performance: Microsoft says excluded files and folders are no longer checked by Defender’s real-time scanning. Only exclude something when you understand the risk and have a clear reason. For an app blocked by Controlled folder access, allow that specific trusted app rather than weakening protection broadly. Microsoft’s scan guide explains how to scan items with Windows Security.
Quick Recap
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