This capability allows customers who want to in-place upgrade their servers to Windows Server 2025 to upgrade using the Windows Update service, and without the need for Windows Server 2025 physical media. On the Windows Server team, we aim for 100% application compatibility, and we are confident that most applications and services will continue to work well after the in-place upgrade to Windows Server 2025.
We recognize that in-place upgrade will not be used by all organizations for all of their servers – some organizations will prefer to perform a clean install, I.E., reformatting the system drive, installing Windows Server 2025, and then re-installing applications and services. Other organizations embrace in-place upgrade because it’s quick and they can avoid re-installing applications and services. Some organizations will use a combination of clean install and in-place upgrade approaches, depending on the role of each server.
To read the full blog post on Microsoft go here