Microsoft Security Essentials Windows 11 May 2026

On Windows 11, is the direct and vastly superior successor to MSE. It is already installed, always updated, and proven to be among the best free antivirus solutions available.

Here’s how Defender on Windows 11 compares to the old MSE: microsoft security essentials windows 11

| Feature | MSE (2009–2015) | Defender on Windows 11 | |--------|----------------|------------------------| | | Yes | Yes, with cloud-delivered AI | | Cloud-based detection | No | Yes (Microsoft Cloud Protection Service) | | Behavioral monitoring | Basic | Advanced (ASR rules, Controlled Folder Access) | | Offline scanning | No | Yes (Microsoft Defender Offline) | | Firewall integration | No | Full Windows Firewall integration | | Account protection | No | Identity protection, sign-in security | | Performance impact | Low | Very low (optimized for modern SSDs/CPUs) | | Update mechanism | Windows Update (optional) | Automatic via Windows Update + security intelligence updates | On Windows 11, is the direct and vastly