KB5089556


Microsoft released cumulative update KB5089556 (Build 28020.2149) for Windows 11, version 26H1 for insiders on the Canary channel. This update includes a number of improvements and changes aimed at increasing system stability, storage usability, and font rendering quality.

Known issues: PC reset. The PC reset process using the Reset this PC feature may freeze. To complete the reset, select Cloud download (Cloud PBR) instead of local reinstallation. This issue has been fixed.

Installation via Windows Update. Go to Settings > Windows Update and click Check for updates. A computer restart is required to complete the installation.

Feature / Change Performance Increase Performance Decrease Optimization PC Speed Gaming Optimization
Improvement of explorer.exe reliability ⚪ None ⚪ None 🟢 Medium — fewer crashes when closing input switcher or switching virtual desktops 🟢 Low — more responsive desktop switching ⚪ No impact
Specify Dev Drive size and volumes in gigabytes ⚪ None ⚪ None 🟡 Low — faster and more precise dev drive creation workflow ⚪ No impact ⚪ No impact
Improvements to Times New Roman font rendering ⚪ None ⚪ None 🟡 Low — more accurate rendering of Greek and Cyrillic diacritics, reducing visual inconsistencies ⚪ No impact ⚪ No impact

Find and Change Settings

Setting Where to find How to change
Dev Drive size in gigabytes Create Dev Drive dialog
Settings > System > Storage > Disks & volumes
When creating a new Dev Drive, type the desired size directly in gigabytes in the size field. To resize an existing volume, navigate to Settings > System > Storage > Disks & volumes, select the volume, click Properties, and enter the new size in gigabytes.
Times New Roman font rendering improvements Automatically applied system-wide No manual change is required. The updated font rendering for combined diacritical marks in Greek and Cyrillic is applied automatically. To verify, open any application using Times New Roman, such as WordPad or Microsoft Word, and type Greek or Cyrillic text with diacritics.

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