KB5094126


Cumulative update KB5094126 for Windows 11 version 25H2 (2025 Update) was released as part of the June 2026 Patch Tuesday. The OS build after installation changes to 26200.8655. The package is intended for devices based on x64 (amd64) and ARM64 processors and includes all previously released fixes from the preliminary update KB5089573 (Build 26200.8524), as well as new features and security improvements.

This update fixes a virtualization issue that could lead to stop errors HYPERVISOR_ERROR (0x20001) and KMODE_EXCEPTION_NOT_HANDLED (0x1E) after installing the previous cumulative package. Failures occurred on some devices during system reboot, during operations with virtual machines, or when launching certain gaming applications.

Installation of cumulative update KB5094126 occurs automatically via Windows Update. To force check, you need to go to Settings, select the Windows Update section and click the Check for updates button. A computer restart is required to complete the installation, after which the build number will change to 26200.8655.

Feature / Change Performance Impact Optimization PC Speed Gaming Optimization
Shared Audio Listening (Bluetooth LE Audio) ⚪ No direct impact 🟡 Medium (Dual audio streaming) ⚪ No impact 🟢 High (Shared game audio without splitters)
Task Manager NPU/GPU neural engine tracking ⚪ No impact (Monitoring only) 🟢 High (Better resource visibility for AI workloads) ⚪ No direct speed change 🟡 Medium (Track AI/ML game-related processes)
Multi-App Camera support 🟢 Low (+~2-5% bandwidth efficiency) 🟡 Medium (Concurrent camera access) ⚪ No impact 🟡 Medium (Stream cam + game cam simultaneously)
Custom user folder name during Setup ⚪ No impact 🟢 Low (Cleaner file paths) ⚪ No impact ⚪ No impact
Shell Performance acceleration 🟢 High (~5-15% faster UI launch) 🟢 High (Start menu, search, Notification Center) 🟢 High (Snappier interaction response) 🟡 Low (Faster overlay/in-game UI calls)
FAT32 formatting limit increased to 2TB ⚪ No direct performance gain 🟡 Medium (Larger legacy volume support) 🟡 Low (Faster format completion for large drives) 🟡 Low (Easier external drive prep for consoles)
Updated Times New Roman (Greek/Cyrillic) ⚪ No impact ⚪ Not applicable (Rendering clarity) ⚪ No impact ⚪ No impact
Windows Search prioritizes at 2 chars (was 3) 🟢 Medium (~10-20% faster results delivery) 🟢 High (Quicker file discovery) 🟢 Medium (Reduced wait time per query) 🟡 Low (Faster config file lookup)
Windows Hello default biometric sign-in 🟢 Low (~0.5-1s faster login) 🟢 High (Streamlined authentication flow) 🟢 Low (Quick desktop access) ⚪ No impact
Secure Boot certificate expansion + limit policy 🟢 Low (Minimal service data overhead) 🟢 High (Phased, controlled deployment) ⚪ No impact ⚪ No direct impact (Stability maintenance)

Find and Change Settings

Setting Where to find How to change
Shared Audio Listening Settings > Bluetooth & devices > Devices Connect two pairs of Bluetooth LE Audio supported headphones. Open Settings > Bluetooth & devices, select your connected LE Audio device, and enable the Shared Audio function to transmit sound simultaneously to both headphones. To stop sharing, disable the function.
NPU / GPU Neural Engine Tracking Task Manager > Performance tab Open Task Manager (Ctrl+Shift+Esc) and go to the Performance tab. NPU and GPU neural engine load columns are now displayed automatically. To hide them, right-click the column header and deselect the relevant items.
Multi-App Camera Settings > Bluetooth & devices > Cameras Select your camera and enable the Multi-App Camera toggle to allow multiple applications to use the camera simultaneously. For basic debugging, turn on Basic Camera mode in the same menu. Disable the toggles to revert.
Custom User Folder Name Windows Setup (OOBE) > Account creation During initial system setup, when creating a local account, enter the desired username. The user folder (C:\Users\) will now match the chosen name. This setting is only available during a clean installation.
Shell Performance (Start, Search, Notifications) N/A (Automatic improvement) This performance update is applied automatically with the OS update. No user action is required to benefit from faster launch times for the Start menu, search, and Notification Center.
FAT32 Formatting Limit (2 TB) Command Prompt (cmd) > format command Open Command Prompt. Use the command format : /FS:FAT32 to format a drive up to 2 TB. The previous 32 GB limit via command line no longer applies.
Updated Times New Roman (Greek, Cyrillic) N/A (Automatic update) The updated fonts are installed automatically with the system update. Applications using Times New Roman will display the improved Greek and Cyrillic glyphs by default.
Windows Search (2-character query) Settings > Privacy & security > Searching Windows Search prioritization now starts after two characters by default. To adjust indexing scope, go to Settings > Privacy & security > Searching Windows and select Classic or Enhanced search mode.
Windows Hello (Face/Fingerprint Default) Settings > Accounts > Sign-in options Sign-in using face or fingerprint is now the default authentication method at every boot. To require password instead, go to Settings > Accounts > Sign-in options and disable "Use Windows Hello as the default sign-in method".
Secure Boot Certificate Deployment Group Policy Editor > Computer Configuration > Administrative Templates > System > Secure Boot To limit transmitted service data, enable the LimitSecureBootRequiredServiceData policy. Devices automatically receive new certificates after successful update signals. Set to Disabled or Not Configured to allow full data transmission.

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