Windows Server 2025.26100.1742-oemret-x64fre-en... Link

If you are running Server 2019 or 2022, direct in-place upgrade to build 26100.1742 is possible only from:

Windows Server 2025 (Build 26100.1742) represents the modern evolution of Microsoft's server operating system, serving as the latest release. This specific build, designated as the General Availability (GA) or "Release to Manufacturing" (RTM) version, was launched on November 1, 2024. Understanding the Version: 26100.1742-OEMRET Windows Server 2025.26100.1742-OEMRET-x64FRE-en...