Microsoft just drew a line in the sand. Windows 11’s built-in Defender Antivirus handles everyday threats for the vast majority of users—no third-party software required. The company laid this out plainly in a support article updated April 9, 2026, stating, “For many Windows 11 users, Microsoft Defender Antivirus covers everyday risk without requiring additional software.” ( Microsoft Windows Learning Center ) This isn’t hype. Defender activates by default. It scans files on open, watches running processes, pulls in cloud intelligence for fresh threats. Add SmartScreen for reputation checks on downloads and sites. Smart App Control blocks unsigned apps. Ransomware protection locks down folders like Documents and OneDrive. All layered. All automatic via Windows Update. But does it hold up? Independent tests say yes. AV-Test in February 2026 gave Defender perfect 6/6 scores across protection, performance, usability. AV-Comparatives real-world tests hit 98.5% to 100% blockage rates.…