Microsoft released cumulative update KB5075941 for Windows 11 version 23H2 (2023 Update) as part of the February Patch Tuesday for 2026. This mandatory security update is intended for Enterprise and Education editions on x64 (amd64) and ARM64 processors and combines fixes from previous releases, including the January update KB5073455 and out-of-band updates KB5077797 and KB5078132. The main goal is to improve system reliability, boot security, and graphics subsystem stability, bringing the build to 22631.6649.
- Secure Boot. Changes have been made to the bootloader for devices with the installed Windows UEFI CA 2023 certificate: the bootmgfw.efi file (signed in 2011) is replaced with a version signed in 2023. The update is deployed in stages — new Secure Boot certificates are installed only on devices that have successfully passed previous checks. When resetting the Secure Boot database or changing its state, a "Secure Boot violation" error may occur, and in rare cases, a special bootable media will be required for recovery.
- Desktop Window Manager (DWM). Fixed an issue where the Desktop Window Manager process could unexpectedly restart, leading to graphics display failures.
- File Explorer. Fixed a folder renaming bug where folders containing a desktop.ini file ignored the LocalizedResourceName parameter, preventing custom folder names from being displayed.
- Fonts and Display. Updated Chinese fonts to support the GB18030-2022A standard, expanded character coverage, and ensured their correct display.
- Graphics (dxgmms2.sys). Fixed an error that, in certain GPU configurations, caused a system crash with a KERNEL_SECURITY_CHECK_FAILURE error related to the dxgmms2.sys file.
- OS Security. Resolved a previously known issue where some PCs with Virtual Secure Mode (VSM) enabled could not properly shut down or enter sleep mode, and instead rebooted.
- Windows Security (SmartScreen). Fixed an error where Microsoft Defender SmartScreen application reputation events (AppRep) were not logged, making it difficult to investigate complex threats.
Installation via Windows Update: cumulative update KB5075941 for PCs is automatically installed via Windows Update for Enterprise and Education editions. To check for availability, open Settings > Windows Update and click Check for updates.
| Feature / Change | Performance Increase/Decrease | Optimization | PC Speed Impact | Gaming Optimization |
|---|---|---|---|---|
| Secure Boot bootloader update (bootmgfw.efi signed 2023) | ⚪ No direct change | 🟢 High (staged deployment, integrity checks) | ⚪ No direct change | ⚪ No direct change |
| Desktop Window Manager (DWM) restart fix | 🟢 High (prevents graphics failures) | 🟢 High (stability) | 🟢 Medium (fewer UI freezes) | 🟢 Medium (less stutter/black screen) |
| File Explorer folder renaming fix (desktop.ini) | ⚪ No impact | 🟡 Low (cosmetic) | ⚪ No impact | ⚪ No impact |
| Chinese font update (GB18030-2022A) | ⚪ No impact | 🟡 Low (character coverage) | ⚪ No impact | ⚪ No impact |
| dxgmms2.sys crash fix (KERNEL_SECURITY_CHECK_FAILURE) | 🟢 High (prevents BSOD) | 🟢 High (stability) | 🟢 Medium (fewer crashes) | 🟢 High (fixes GPU-related crashes) |
| VSM shutdown/sleep fix | 🟢 Medium (proper power state) | 🟢 Medium (power management) | 🟢 Low (correct shutdown/sleep) | ⚪ No direct impact |
| SmartScreen AppRep logging fix | ⚪ No impact | 🟢 Medium (security telemetry) | ⚪ No impact | ⚪ No impact |
Find and Change Settings
| Setting | Where to find | How to change |
|---|---|---|
| Secure Boot | Settings > System > Recovery > Advanced startup > Troubleshoot > Advanced options > UEFI Firmware Settings | Restart the PC into UEFI firmware settings. The 2023 certificate is installed automatically after passing validation checks. If a "Secure Boot violation" error occurs after resetting the Secure Boot database, use a special bootable recovery media to restore the boot configuration. Do not manually change the Secure Boot state unless required. |
| Desktop Window Manager (DWM) | No user setting — automatic system component | This is a system-level fix. No manual change is required. The DWM process no longer restarts unexpectedly, preventing graphics display failures. |
| File Explorer Folder Renaming | File Explorer > Folder properties > Customize | Folder names with desktop.ini now respect the LocalizedResourceName parameter. To customize a folder name, create or edit desktop.ini inside the folder and set LocalizedResourceName to the desired display name. |
| Chinese Fonts (GB18030-2022A) | Settings > Time & language > Language & region > Chinese language options | The updated fonts are applied automatically after the update. No manual change is required. The fonts now support GB18030-2022A and display expanded characters correctly. |
| Graphics (dxgmms2.sys) | No user setting — automatic system fix | This is a system-level fix. No manual change is required. The KERNEL_SECURITY_CHECK_FAILURE error related to dxgmms2.sys no longer occurs in affected GPU configurations. |
| OS Security (VSM Shutdown/Sleep) | Settings > Privacy & security > Device security > Core isolation | The fix is applied automatically. PCs with Virtual Secure Mode (VSM) enabled can now shut down or enter sleep mode normally. No manual change is required. |
| Windows Security (SmartScreen AppRep Logging) | Windows Security > App & browser control > Smart App Control settings | The fix is applied automatically. Microsoft Defender SmartScreen application reputation events (AppRep) are now logged correctly. No manual change is required. |
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 |