Build 26300.8376 is a newer Windows 11 Insider Preview build for the Dev/Experimental Channel, continuing the transition to the new Windows Insider Program channel structure and the 25H2 baseline.
Recent Experimental/Dev builds (26300.8289 and 26300.8346) are based on Windows 11, version 25H2 via the KB5054156 enablement package and use Controlled Feature Rollout (CFR) to gradually deliver new features. Build 26300.8376 follows this same pattern: it is offered through Windows Update to devices enrolled in the Dev/Experimental Channel and will appear as a normal Insider pre-release update with the desktop watermark.
Key points relevant to 26300-series Dev/Experimental builds:
- They are Windows 11, version 25H2 builds delivered via an enablement package (KB5054156).
- Many features are controlled by CFR and may not appear for all devices immediately.
- New Windows Update capabilities (such as skipping updates during OOBE, extending pauses, and improved update insights) are being rolled out in this channel.
- Channel movement from Dev to the new Experimental channel is in progress and can be influenced via Settings > Windows Update > Windows Insider Program > Feature flags.
If 26300.8376 is showing as available in Windows Update on a device enrolled in Dev/Experimental, it is the expected next Insider flight in this 26300 branch and can be installed directly from Windows Update.
References:
- Windows 11 Insider Experimental Preview Build 26300.8346
- Windows 11 Insider Experimental Preview Build 26300.8289
- Set up a Dev Drive on Windows 11
- How to install 25H2 enablement package? - Microsoft Q&A
- Any Updates from windows 11 release preview 26220.6690 - Microsoft Q&A
- My system has been on RP channel why is it downloading a Beta release? - Microsoft Q&A
- Release Preview channel seems to be missing - Microsoft Q&A