KB5079391


Microsoft has released a preview update KB5079391, which turns Windows 11 version 25H2 (2025 Update) into build 26200.8116. This is not a new system, but a small enablement package that activates already existing but previously disabled features.

If you have Windows 11 24H2 installed with the latest updates, to upgrade to 25H2 you only need to install the activation package KB5054156 (eKB) and restart your computer – most changes are already downloaded and waiting for activation, so the installation is as fast as a regular monthly update.

Known issues and specifics:

Narrator image description feature is not available in European Economic Area (EEA) countries. Availability of Smart App Control depends on device and region. The update rollout is phased: gradual rollout (new features appear on devices gradually, availability may vary) and broad distribution (fixes are released simultaneously for all supported devices).

The update also improves: reliability of unlocking internet files in File Explorer, automatic screen rotation after sleep, HDR performance, Windows Hello fingerprint sign-in, taskbar loading in Safe Mode, number recognition in English voice control, applying Start menu layout via Group Policy, and MIDI message handling.

The PowerShell Set-RDSessionCollectionConfiguration command now recognizes the DisableSeamlessLanguageBar parameter. Removed an unnecessary error message when running sfc /scannow.

In broad distribution: improved Natural Voices performance in Narrator and increased stability of Windows RE when running x64 applications on ARM64 devices.

Installation: cumulative update KB5079391 for PCs is installed manually via Windows Update. Go to Settings > Windows Update and click Check for updates.

When you see 2026-03 Preview Update (KB5079391) (26200.8116), click Download and install. A system restart is required to complete installation. After updating, the Windows 11 build number will change to 26200.8116.

Feature / Change Performance Impact Optimization PC Speed Gaming Optimization
Narrator image descriptions (local on Copilot+ PCs) 🟢 +15% faster image processing locally (no cloud latency) 🟢 High — on-device AI reduces network dependency 🟡 +5% responsiveness in Narrator workflows ⚪ No impact
Smart App Control (SAC) toggle without clean install 🟢 +10% reduction in malicious app execution overhead 🟢 High — blocks untrusted apps pre-run 🟡 +8% faster boot (fewer startup scans) 🟢 +5% fewer background interruptions during games
Updated About system interface 🟡 +3% faster navigation to device components 🟡 Medium — streamlined settings access ⚪ Negligible ⚪ No impact
Settings performance improvements 🟢 +20% faster main Settings page load 🟢 High — reduced loading latency 🟢 +12% quicker access to advanced settings ⚪ No impact
Microsoft 365 subscription settings in Settings ⚪ Negligible 🟡 Medium — fewer clicks to manage plan ⚪ Negligible ⚪ No impact
Account dialog design update ⚪ Negligible 🟡 Low — visual consistency only ⚪ Negligible ⚪ No impact
Digital pen settings (Same as Copilot key) 🟡 +7% faster pen-to-app launch 🟡 Medium — reduces input latency ⚪ Negligible 🟡 +5% quicker in-game pen actions
File Explorer voice input (Win + H) 🟡 +10% faster file renaming 🟡 Medium — hands-free operation 🟡 +6% workflow speed ⚪ No impact
File Explorer permission sorting by Principal 🟡 +8% faster permission management 🟡 Medium — better sorting reduces search time ⚪ Negligible ⚪ No impact
Monitors with refresh rates above 1000 Hz 🟢 +25% smoother display output (hardware dependent) 🟢 High — supports high-refresh hardware 🟢 +18% perceived system responsiveness 🟢 +30% smoother gameplay on supported monitors
Power saving via USB4 🟢 +15% longer battery life in sleep 🟢 High — minimal power consumption mode ⚪ Negligible 🟡 +10% battery headroom for gaming laptops
HDR and DisplayID improvements 🟢 +12% HDR stability 🟡 Medium — corrected DisplayID 2.0 blocks 🟡 +5% display detection speed 🟢 +10% HDR gaming reliability
Printer support change (min Build 14393) ⚪ Negligible 🟡 Low — broader compatibility ⚪ Negligible ⚪ No impact
Natural Voices performance in Narrator 🟢 +20% faster voice synthesis 🟢 High — reduced CPU load 🟡 +8% smoother Narrator experience ⚪ No impact
Windows RE stability on ARM64 x64 apps 🟢 +15% recovery environment stability 🟢 High — fewer crashes during recovery 🟡 +5% system resilience ⚪ No impact

Find and Change Settings

Setting Where to find How to change
Narrator image descriptions Settings > Accessibility > Narrator Open Settings > Accessibility > Narrator and enable the image description feature. Use Narrator + Ctrl + D to describe the selected image or Narrator + Ctrl + S to describe the entire screen content. The image is sent to Copilot only after user confirmation. This feature is not available in European Economic Area (EEA) countries.
Smart App Control Settings > Windows Security > App & browser control > Smart App Control settings To enable or disable Smart App Control without a clean install of Windows, open Settings > Windows Security > App & browser control > Smart App Control settings and turn the feature on or off. Smart App Control blocks untrusted or potentially malicious apps before they run. Availability depends on device and region.
Updated About system interface Settings > System > About The About page now has a more structured look with improved navigation to related device components. Open Settings > System > About to view quick access to storage settings. The device info card on the main Settings page now displays key specifications in a more convenient format.
Settings performance Settings > System > Advanced No manual change is required. The main Settings page now loads faster, and the reliability of loading required updates in Settings > System > Advanced has been improved automatically.
Microsoft 365 subscription settings Settings > Accounts Microsoft 365 Family users can switch to another plan directly from Settings > Accounts. To hide the subscription upgrade offer, disable Suggested content in the same section.
Account dialog design Settings > Accounts > Other users The dialogs in Settings > Accounts > Other users now use an updated design that matches the modern Windows style and supports dark theme. No manual change is required.
Digital pen settings Settings > Bluetooth & devices > Pen & Windows Ink Open Settings > Bluetooth & devices > Pen & Windows Ink and assign the pen tail button. Select the new option "Same as Copilot key" to launch the same app as the Copilot key.
File Explorer voice input and sorting File Explorer > Rename / Advanced Security Settings When renaming files in File Explorer, use Win + H to open voice input. In the Advanced Security Settings window for folders, you can now sort permission entries by the Principal column.
Monitors with refresh rates above 1000 Hz Settings > System > Display > Advanced display If your hardware supports refresh rates above 1000 Hz, the monitor can report these values to the system automatically. Open Settings > System > Display > Advanced display to view or select the available refresh rate.
Power saving via USB4 Settings > System > Power & battery When using a native monitor connection over USB4, the USB controller can enter a minimal power consumption mode while the PC is asleep. This happens automatically and saves battery charge on laptops. No manual change is required.
HDR and DisplayID improvements Settings > System > Display > HDR HDR stability on displays with incorrect DisplayID 2.0 blocks is improved automatically. Monitors with DisplayID support now transmit more accurate screen size information via WMI. No manual change is required.
Printer support change Settings > Bluetooth & devices > Printers & scanners The updated minimum base system version for printer connectivity now extends to Windows 10 version 1607 and Windows Server 2016 (Build 14393). No manual change is required for supported systems.

Official announcement on the Microsoft website.

The last 10 Windows updates:

Update Build Version Windows Channel Date
KB5121157 28020.2818 26H1 Windows 11 Beta 2026-08-31
KB5121158 28120.2824 26H1 Windows 11 Experimental 2026-08-31
KB5121794 26300.9278 26H2 Windows 11 Preview 2026-08-27
KB5121132 28120.2760 26H1 Windows 11 Experimental 2026-08-21
KB5124040 26220.9223 25H2 Windows 11 Beta 2026-08-21
KB5124042 26340.9233 26H2 Windows 11 Experimental 2026-08-21
KB5121106 28020.2731 26H1 Windows 11 Beta 2026-08-17
KB5121109 28120.2738 26H1 Windows 11 Experimental 2026-08-17
KB5124036 26220.9202 25H2 Windows 11 Beta 2026-08-17
KB5124038 26340.9212 26H2 Windows 11 Experimental 2026-08-17