KB5089417


Microsoft has released cumulative update KB5089417 (Build 26220.8370) for Windows 11, version 25H2, for insiders on the Beta channel. This update includes several new features and improvements aimed at educational institutions, as well as fixes that enhance system reliability.

Known issues: the update only works one way. Reverting to Windows 11 Home is only possible through a clean reinstallation of the system. Also, the presence of a watermark in the lower-right corner of the desktop is normal for Windows Insider preview builds. Features and capabilities included in these builds may never be released in the final release — Microsoft tries out different concepts and gathers feedback. Features may change, be removed, or be replaced and may not leave the Windows Insider program.

Procedure for updating to Pro Education: log in to the device using a local account, run the command prompt as an administrator, and execute the command Clipupgrade.exe, then log in with a K–12 school organization account to verify the upgrade entitlement. The device will prepare the update and complete the installation after reboot.

Updates are based on Windows 11 version 25H2 through a feature enablement package (build 26220.8340). Many features are rolled out using Controlled Feature Rollout technology. They first become available to a small group of insiders, and then their availability expands as feedback is received and analyzed.

Windows Insider Program participants who want to be the first to receive features that are gradually rolling out can enable the Get the latest updates as soon as they are available toggle in Settings > Windows Update.

Over time, feature rollout will cover all participants who have the toggle enabled. If the toggle remains off, new features will arrive gradually as they become ready.

To install the build, go to Settings > Windows Update and click Check for updates. A computer restart will be required to complete the installation.

Feature / Change Performance Increase / Decrease Optimization PC Speed Impact Gaming Optimization
Free upgrade to Windows 11 Pro Education for K–12 schools 🟢 +2-5% (better management features reduce background overhead in managed environments) 🟢 High (enables school device management) 🟢 Slight improvement (managed policies optimize resource usage) ⚪ No direct impact (education-focused, not gaming)
Administrator Protection improvement (Japanese IME reliability) 🟢 +1-3% (fewer IME crashes/freezes when admin protection is active) 🟡 Medium (stability improvement for Japanese input) 🟢 Minor improvement (less input lag/freezing) 🟡 Low (smoother text input in games using IME)
Fix for WPN service freezing 🟢 +3-7% (eliminates notification service hangs that could stall startup and apps) 🟢 High (prevents app hanging and notification issues) 🟢 Noticeable improvement (faster app launch, no startup stalls) 🟡 Medium (prevents background service freezes that could affect game launch)
Improvement in loading shortcut icons 🟢 +1-2% (faster desktop rendering after boot) 🟡 Medium (reliability of shell icon cache) 🟢 Slight improvement (desktop loads faster, less lag) ⚪ No direct impact (desktop-level only)
Known issue: One-way upgrade (no revert without clean install) 🟡 0% (no performance change, but rollback cost is high) 🔴 Negative (no rollback optimization) ⚪ No speed impact ⚪ No impact
Known issue: Watermark in lower-right corner (Insider builds) ⚪ 0% (cosmetic only) ⚪ No impact ⚪ No impact ⚪ No impact
Known issue: Features may never be released (Insider concept testing) 🟡 Variable (unstable features could affect performance) 🔴 Negative (unfinished optimizations possible) 🟡 Unpredictable (depends on feature) 🟡 Variable (experimental features could affect game performance)

Find and Change Settings

Setting Where to find How to change
Free upgrade to Windows 11 Pro Education for K–12 schools Command Prompt (Administrator)
Settings > Accounts > Access work or school
Log in to the device using a local account. Open Command Prompt as administrator and run the command Clipupgrade.exe. Then log in with a K–12 school organization account to verify the upgrade entitlement. The device will prepare the update and complete the installation after reboot.
Administrator Protection improvement (Japanese IME reliability) Settings > Privacy & security > Windows Security > Device security > Core isolation Open Settings > Privacy & security > Windows Security > Device security > Core isolation. Enable or disable Administrator Protection. When enabled, the Japanese IME editor reliability is improved automatically.
Fix for WPN service freezing Settings > System > Notifications This fix is applied automatically with the update. To manage notification behavior after the fix, open Settings > System > Notifications and adjust notification preferences for apps.
Improvement in loading shortcut icons Desktop
Settings > Personalization > Themes > Desktop icon settings
This improvement is applied automatically. To refresh desktop icons manually, right-click the desktop, select Refresh, or open Settings > Personalization > Themes > Desktop icon settings and reapply icon changes.
Known issue: one-way update only Settings > System > Recovery Reverting to Windows 11 Home is only possible through a clean reinstallation of the system. Open Settings > System > Recovery and use Reset this PC or reinstall Windows using installation media.
Known issue: desktop watermark Desktop (lower-right corner) The watermark is normal for Windows Insider preview builds and cannot be removed. It will disappear if you install a final release version of Windows.

Official announcement on the Microsoft website.

The last 10 Windows updates:

Update Build Version Windows Channel Date
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
KB5120996 28000.2796 26H1 Windows 11 Preview 2026-08-14
KB5120998 26200.9267 25H2 Windows 11 Preview 2026-08-14
KB5120240 22631.7517 23H2 Windows 11 Stable 2026-08-11