Windows 11 Insider Preview 28000.1 (br_release) - Error message – 0xc1900101

The 0xC1900101 error is almost always driver-related, even if everything looks up to date. A few things you can try that usually fix it:

Disconnect all non-essential devices (USB drives, hubs, audio interfaces, external GPUs, etc.).

Update or temporarily remove third-party antivirus/security tools, as they often block Canary builds.

Check Device Manager for hidden devices with warnings and remove any old/unused drivers.

Run sfc /scannow and DISM /online /cleanup-image /restorehealth to repair system files.

In Windows Update settings, pause updates → restart → resume and try again.

If it still fails, try in-place upgrade via the Canary ISO—this bypasses some upgrade checks.

This error usually clears once the conflicting driver or service is removed.