Microsoft Windows 11 build 28000.2804 (KB5120996) is an optional non-security preview update for Windows 11 version 26H1, introducing new features, quality improvements, and reliability enhancements.

What's new

• Improves File Explorer with easier-to-read file sizes, middle-click folder tabs, improved thumbnails, and reliability fixes.
• Adds Voice Isolation and Korean language support to Voice Access.
• Extends Windows Hello Enhanced Sign-in Security (ESS) support to compatible external fingerprint sensors.
• Improves Windows Search handling of typos, partial application names, and Settings relevance.
• Improves power settings reliability and restores the configurable Energy Saver activation threshold.
• Improves DHCP renewal reliability, particularly when receiving NACK responses and on Modern Standby devices.
• Improves IPPS printer performance and Remote Desktop and Azure Virtual Desktop clipboard reliability.
• Improves explorer.exe, Windows sign-in, lock screen, Start menu, and taskbar reliability.
• Includes Windows Update cleanup improvements designed to improve system performance following an update.
• Updates AI components on supported Copilot+ PCs to version 1.2607.840.0.

Known issues

• Microsoft Teams and the new Outlook might fail to launch or close unexpectedly on some ARM-based devices. Microsoft states that this issue is resolved by the September 8, 2026 update KB5124012 or later.

Recommendation

As KB5120996 is an optional non-security preview update, broad enterprise deployment is not required. Organizations may deploy it to pilot devices when specific fixes or new functionality are required, while production environments can otherwise wait for the subsequent cumulative security update that incorporates these improvements.