x64-based and ARM64-based systems running Windows 11 version 21H2.
KB5031358 was deployed as part of Microsoft's regular Patch Tuesday cycle [1]. It automatically upgrades the Windows 11 build number to . It targets critical internal vulnerabilities, aiming to prevent remote code execution and improve overall OS stability [1]. Key Features and Fixes 1. Introduction of Windows Copilot
KB5031358 is a "must-install" for the security fixes alone, but it represents a shift in how Microsoft views Windows 11. It is no longer a static OS waiting for a version 23H2 release. Through this update, your Windows 11 experience is dynamically altered, bringing AI to the forefront and retiring legacy interfaces. x64-based and ARM64-based systems running Windows 11 version
Includes elements from the "Moment 4" update, such as a preview of Copilot in Windows , a new Windows Backup app , and updates to the Settings app and Taskbar .
: A Skype for Business elevation of privilege flaw exposing internal server vulnerabilities. It is no longer a static OS waiting
System file corruption can prevent cumulative patches from modifying core OS components.
) while trying to install this update on x64 systems. Standard troubleshooting steps include: Microsoft Learn Windows 11 Update KB5031358 Install Error (0x800f0988) a new Windows Backup app
No cumulative update is without risks. Some users reported after installing KB5031358:
and served as the final security patch for the Home and Pro editions of this version as they reached their end of support. Critical Security Fixes
Corrupted background download segments often block installation loops.
Mandatory cumulative updates can occasionally encounter installation errors such as 0x800f081f , 0x80070002 , or indefinite progress loops. Use these steps to resolve deployment blocks. Reset Windows Update Components