Microsoft released cumulative update KB5077181 for Windows 11 version 25H2 (2025 update) as part of the February 2026 Patch Tuesday. The cumulative package KB5065426 (builds 26200.7840 and 26100.7840) is intended for Windows 11 version 25H2 on x64 (amd64) and ARM64 processors.
Windows 11 version 25H2 is not a new operating system, but a small feature update (an enablement package) that activates existing but previously unused capabilities. Simply put, if you have Windows 11 24H2 installed with the latest updates, moving to version 25H2 only requires downloading and installing the activation package KB5054156 (eKB) and restarting your computer. Most of the changes are already downloaded and waiting for activation, so the installation happens as quickly as a regular monthly update, and after completion you will get all the new features that were previously inactive on your system.
- Gaming. Fixed an issue where device compatibility with full-screen gaming mode was incorrectly determined.
- Networking. Addressed an error that prevented some devices from connecting to certain Wi-Fi networks protected by WPA3-Personal. This problem could occur after installing update KB5074105.
- Secure Boot. Microsoft is updating the certificates used to verify trusted components during Windows startup. To avoid situations where some PCs may experience startup problems after the update, deployment will be gradual and limited to devices with a confirmed history of stable update installations.
Cumulative update 5077181 for PCs is installed automatically through Windows Update. To check this, go to Settings > Windows Update and click Check for updates.
A system restart is required to complete the installation. After the update, the Windows 11 build number will change to 26200.7840 or 26100.7840.
Find and Change Settings
Gaming: Fixed an issue where device compatibility with full-screen gaming mode was incorrectly determined. The graphics driver (DWM) now correctly checks Flip Model and MPO support flags before switching to exclusive mode, preventing false blocking.
Networking: Addressed a Wi-Fi connection failure with WPA3-Personal after KB5074105. The issue was caused by incorrect pairwise negotiation during 4-way handshake — the client sent an invalid group key parameter. Fixed logic in wlansec.dll for AKM authentication.
Secure Boot: Microsoft is updating certificates for validating bootloaders and drivers. New trusted root certificates are added to the UEFI db (Signature Database). Deployment is limited to devices with stable update history to avoid scenarios where old bootloaders fail verification (efi_validate returns EFI_SECURITY_VIOLATION).
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 |