Builds 26100.8328 and 26200.8328 are Release Preview (RP) channel preview builds that are delivered through Windows Update as a cumulative update (KB5083631).
To get them on a device already enrolled in the Release Preview Channel:
- Ensure the device is on a supported Windows 11 baseline (26100 or 26200 series) and enrolled in the Windows Insider Release Preview Channel.
- Open Settings → Update & Security → Windows Update.
- Select Check for updates.
- When the Release Preview cumulative update for KB5083631 appears, allow it to download and install.
- Restart the device when prompted to complete installation; the OS build will then show as 26100.8328 or 26200.8328, depending on the base build.
These preview builds follow the same servicing model as other cumulative updates: the latest servicing stack update (SSU) is combined with the latest cumulative update (LCU) or hotpatch where applicable, and they are delivered automatically via Windows Update/Windows Update for Business when available to the configured channel.
References:
- September 30, 2024—KB5043178 (OS Build 26100.1882) Preview
- May 28, 2025—KB5058499 (OS Build 26100.4202) Preview
- January 13, 2026—KB5074109 (OS Builds 26200.7623 and 26100.7623)
- January 24, 2026—Hotpatch KB5078167 (OS Builds 26200.7634 and 26100.7634) Out-of-band
- February 10, 2026—Hotpatch KB5077212 (OS Builds 26200.7781 and 26100.7781)