Microsoft has released cumulative update KB5074178 for Windows 11 version 25H2 for insiders in the Dev Channel – this is a Windows 11 Insider Preview quality update (26300.7733). Windows 11 Insider Preview Build 26300.7733 (KB5074178) has been released.
Users in this channel will now receive updates for Windows 11 version 25H2, which are provided via the enablement package KB5073032 (build 26300.xxx). The Dev Channel includes the latest Windows 11 preview builds with new features. These builds may have lower stability and some issues, but they are intended for enthusiasts who want to try new operating system features in advance.
- Built-in Sysmon support. Microsoft is integrating Sysmon directly into Windows 11 and Windows Server 2025. The Dev Channel now has built-in Sysmon support – a system monitoring tool previously available separately as part of the Sysinternals suite. Sysmon functionality is now integrated directly into the operating system. Sysmon allows logging of system events useful for threat detection and security analysis, and also allows custom configuration files to filter tracked events. All collected data is written to the Windows Event Log, making it easier to use in security tools and analysis scripts.
- Voice Access support for Dutch. Added support for the Netherlands (Dutch) language for the Voice Access feature, expanding the list of supported locales and improving the accessibility of hands-free voice control in Windows.
- Fix for application freezes when working with cloud files. Fixed an issue that could cause applications to freeze when working with files stored in cloud services such as OneDrive or Dropbox. In some configurations, Outlook with PST files hosted in OneDrive could freeze or repeatedly reload mail data.
Updates for Windows insiders in the Dev Channel are delivered based on Windows 11 version 25H2 via the enablement package (builds 26300.xxxx).
Installation via Windows Update: go to Settings > Windows Update and click Check for updates. A computer restart is required to complete installation.
Note: If Sysmon was previously installed manually from the Sysinternals website, it must be removed before enabling the built-in version. The core functionality of Sysmon remains unchanged.
| Feature / Change | Performance Increase / Decrease | Optimization | PC Speed | Gaming Optimization |
|---|---|---|---|---|
| Built-in Sysmon support | 🟡 Minor decrease (background logging overhead) | 🟢 High (native system monitoring, no external tool needed) | ⚪ Neutral (negligible impact on everyday tasks) | ⚪ Neutral (no direct effect on gaming) |
| Voice Access support for Dutch | ⚪ No change | 🟡 Medium (accessibility expansion, minor resource use) | ⚪ Neutral | ⚪ Neutral |
| Fix for application freezes when working with cloud files | 🟢 Moderate improvement (eliminates freeze-related slowdowns) | 🟢 High (stable file access for OneDrive/Dropbox/Outlook PST) | 🟢 Moderate improvement (smoother file operations) | ⚪ Neutral |
Find and Change Settings
| Setting | Where to find | How to change |
|---|---|---|
| Built-in Sysmon support | Event Viewer > Applications and Services Logs > Microsoft > Windows > Sysmon | Sysmon is now built into the operating system. To configure it, deploy a Sysmon configuration file using your preferred management method (for example, Group Policy, Intune, or manual placement). Collected events are written to the Windows Event Log under Applications and Services Logs > Microsoft > Windows > Sysmon. Use the Event Viewer or your security tools to view and analyze the logged events. Custom configuration files can be used to filter which events are tracked. |
| Voice Access support for Dutch | Settings > Accessibility > Speech | To use Voice Access in Dutch (Netherlands), open Settings > Accessibility > Speech and select Dutch as the voice access language. You may need to download the required language pack first. Once selected, enable Voice Access to use hands-free voice control. To disable it, return to Settings > Accessibility > Speech and turn Voice Access off. |
| Fix for application freezes when working with cloud files | No user setting required; fix is applied automatically with the update. | This is a system fix and requires no manual configuration. After installing the update, applications such as Outlook with PST files hosted in OneDrive or Dropbox should no longer freeze or repeatedly reload mail data. If issues persist, ensure the update is installed and restart the affected application or the PC. |
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 |