Windows 11 Update KB5077181 Security and AI Evolution
The February 2026 cumulative update, KB5077181, represents a major transformation for Windows 11 operating system. The update contains two new features which include local AI models and solutions for vital hardware communication problems. The update supports both 24H2 and 25H2 versions while increasing the build numbers to 26100.7840 for 24H2 and 26200.7840 for 25H2.
The update file size exceeds 4GB which makes it one of the largest updates available. The size of the file increases because it contains local AI models which include the on device model called "Phi." Microsoft has decided to install essential files on all computers because the models need a modern NPU (40+ TOPS) to run properly and they plan to use AI in upcoming tasks.
| Feature | Version 24H2 | Version 25H2 |
|---|---|---|
| Build Number | 26100.7840 | 26200.7840 |
| Update Size | 4479.7 MB | 4479.7 MB |
| Service Stack (SSU) | KB5077869 (Mandatory) | KB5077869 (Mandatory) |
Critical Security Patches Addressing Zero Day Threats
The security update KB5077181 requires mandatory installation. The patch resolves 58 security issues which include six "Zero Day" vulnerabilities that hackers actively exploit. The update provides essential fixes which include
- CVE 2026 21510 The fix resolves a Windows Shell security flaw which enabled attackers to create deceptive links that misled users.
- CVE 2026 21519 The fix resolves a security flaw in Desktop Window Manager which attackers could use to acquire SYSTEM level privileges.
- Secure Boot Update Microsoft is replacing 2011 certificates with modern 2023 certificates. The update checks system readiness to prevent boot failures before the certificates expire in mid 2026.
Cross Device Resume
Users can now transfer their work between Android devices (Samsung, Honor, Oppo, Xiaomi) and their Windows computers. Currently supporting Spotify and Microsoft 365, a task started on your phone will trigger a notification on your PC taskbar, allowing you to resume instantly via cloud synchronization.
MIDI 2.0 Infrastructure
Microsoft has developed a completely new MIDI service for musicians and music creators. The new system supports MIDI 2.0 and allows multiple applications to connect to the same MIDI hardware through "Shared Ports" which enables shared access with lower latency.
Smart App Control (SAC) Toggle
Microsoft has addressed user feedback regarding Smart App Control. Previously, changing this setting required users to perform a complete OS reinstallation. Windows Security now permits users to activate or deactivate SAC without needing to restart their entire system.
This update includes a major fix which resolves problems with "Modern Standby" battery drain. The systems now contain protective features which identify ordinary power use when the device stays shut down. The system prevents background processes from activating the device needlessly which helps to conserve battery power while stopping devices from considering everything as active.
Reddit users have reported several minor issues that affect this build according to community feedback.
- UAC for Storage Settings Accessing storage settings now triggers a User Account Control (UAC) prompt for admin rights, which can slow down basic maintenance for standard users.
- Gaming Performance Some users have reported minor stuttering in titles like Kingdom Come Deliverance 2. This is often linked to older NVIDIA drivers; updating to the latest GPU driver is recommended.
- Lock Screen Bug A minor visual glitch has been noted where the password icon disappears from the lock screen, though the input field remains functional.
The zero day security patches together with the battery life enhancements make KB5077181 installation highly necessary. To achieve optimal performance you must update your graphics drivers before proceeding with the installation. Manual download of the update from Microsoft Update Catalog becomes necessary when users face installation errors.
