Windows 10 is out of mainstream support, but Microsoft Defender never left town. If you’re hanging tight for the time being, Defender continues to provide useful protection — just not a replacement for missing operating system patches. Here’s a no-nonsense look at what it can and cannot do for a 2025-era machine running Windows 10.
What Defender Still Does Well on Windows 10
And Microsoft Defender Antivirus will continue to receive security intelligence and engine updates on Windows 10, with real-time detection for viruses, ransomware, and other malware. Microsoft has pledged continued signature and platform updates for many years following Windows 10’s end of support, with core protections being covered into at least late 2028 according to their own documentation.
Cloud-delivered protection and behavior monitoring are not impacted on Windows 10. When turned on, both features work in near-real-time to analyze suspicious activity and can shut down emerging threats that classic signatures don’t catch; Tamper Protection stops malware from disrupting your security settings and Microsoft Defender Offline can root out deeply hidden infections with a reboot scan.
Core hardening tools remain in place: Controlled Folder Access can stop many ransomware strains from encrypting your documents; Exploit Protection applies systemwide mitigations; and the built-in firewall still enforces inbound and outbound rules.
SmartScreen adds to web and download safety (especially in Edge) by incorporating reputation-based blocking for any executable that doesn’t look kosher.
Defender’s raw detection is a favorite of independent labs. AV-TEST has repeatedly given it top marks for protection, and AV-Comparatives’ real-world tests consistently demonstrate close to 100% block rates against active threats. The trade-off: Defender has reported above-average false positives in some rounds, so review quarantines before deleting.
Where Defender Falls Short on Windows 10 Systems
Defender cannot patch Windows. Unsupported systems are left out in the cold when cumulative updates arrive that fix kernel, driver, or privilege-escalation vulnerabilities. One more thing: anti-malware can block known malware, but it cannot remove an unpatched vulnerability allowing code execution in the first place. There are high-impact bugs — think print spooler, LPE-style issues — where there’s no OS fix, resulting in a permanently open attack surface.
There are also defensive tools that are based on a certain version. Virtualization-based security, kernel-mode hardening, and new exploit mitigations rely on system components for which there will be no further evolution on Windows 10. SmartScreen and browser protections can help, but they don’t supplant the modern memory protections and credential isolation in current versions of Windows.
Defender also doesn’t handle third-party patching. Obsolete browsers, old Java runtimes, aging PDF readers, and out-of-date drivers remain high-reward entry points. Even the best malware detection has flaws, and unpatched apps open pathways for malicious documents, ad networks, and compromised sites to infect your device.
Defender for Endpoint vs. the Built-in Antivirus
Businesses on Windows 10 can rely on Microsoft Defender for Endpoint, which is more than consumer Defender, with endpoint detection and response, threat hunting, and attack surface reduction rules. Microsoft does support down-level onboarding for end-of-life systems, such as older versions of Windows, but some functionality may be restricted by the OS.
Home users: You will be stuck with integrated Defender Antivirus without EDR telemetry, advanced ASR rules, and automated remediation workflows. It is still strong as a baseline, but businesses must not confuse it with enterprise-class visibility and response.
How to Optimize Microsoft Defender on Windows 10
Turn on cloud-delivered protection and automatic sample submission in Windows Security. Turn on Controlled Folder Access in your document libraries, and review allowed apps to avoid being prompted too much. Keep Exploit Protection at its defaults or pull in known profiles for high-risk apps like browsers, PDF readers, and office suites.
Harden everyday use: Use a standard user account, disable Office macros from the internet, remove legacy components that are no longer needed (like SMB1), and keep browsers and extensions updated.
Then pair Defender with disciplined backup (e.g., versioned, offline, immutable storage) to mitigate ransomware’s worst impacts.
Add network-layer safety nets. Employ a trusted DNS filtering service that will block all known malicious domains, update router firmware, and turn on multi-factor authentication for crucial accounts. These controls help minimize the blast radius when phishing or drive-by attacks bypass the first layer of defense.
When to Add a Security Suite or Upgrade from Windows 10
If you have many PCs, require fine-grained content filtering, or desire identity monitoring, a third-party security suite can provide Defender with some help.
Seek out high exploit protection and low false positives in the latest tests from AV-TEST and AV-Comparatives. Of course, there are features that don’t play nice together, but you just can’t run two real-time antivirus engines at once.
For longer-term safety, you may want to consider extended security updates or migrating to Windows 11. Microsoft has its Extended Security Updates program that organizations can pay for to receive support for up to three years through a number of procurement paths. If your device has sensitive data or regulatory requirements to meet, the calculus tips in favor of sticking with a supported OS and not using antivirus as the only way to protect yourself.
Bottom Line for Using Defender on Windows 10 Today
Microsoft Defender on Windows 10 still does an excellent job of blocking bad stuff. But no antivirus, by itself, can stand in for gaps in your OS updates and current protections. Use Defender as a baseline, harden the system around it, and have a plan for security updates or an upgrade path before attackers make that decision for you.