Microsoft's March updates patch 83 flaws and debut Arm-optimized Windows 11 26H1

Microsoft has rolled out its March updates for multiple Windows versions, including Windows 11 25H2, 24H2, and the newly introduced 26H1. The release also covers Windows 10, Microsoft Office, and server environments. Among the changes are security fixes, performance improvements, and new features like a built-in network speed test.

The updates address 83 security flaws, some rated as critical, while also introducing enhancements to File Explorer and Secure Boot certificates.

The March updates bring security patches for 83 vulnerabilities, with some scoring as high as 9.8 on the CVE severity scale. These fixes apply across Windows 11, Windows 10, Microsoft Office, and cloud-based systems. Windows 10 users still receiving Extended Security Updates (ESU) are also included in this release.

For Windows 11, the updates extend to versions 25H2, 24H2, and the newly launched 26H1—Microsoft's first build optimised for Arm devices using Qualcomm's Snapdragon X2 processors. This marks the initial update for the 26H1 branch. Users will notice improvements in File Explorer, particularly when searching across multiple drives or within the 'This PC' section. Another addition is a network speed test, accessible directly from the taskbar. The feature opens as a web app via Bing Search, though exact usage statistics remain unavailable. On the security front, Microsoft has updated Secure Boot certificates. Older certificates will expire in June 2026, requiring users to install the new ones to maintain system protection.

The March updates deliver critical security fixes alongside functional upgrades for Windows users. The changes affect multiple versions, including the new Arm-focused Windows 11 26H1. Users are advised to install the updates to benefit from the latest protections and features.