You should see MSSQLLocalDB as the default instance.

There is no official "portable" version (e.g., a "run-from-USB" executable) of . SQL Server is a complex service-based engine that requires deep integration into the Windows OS to run properly.

If you search for "MS SQL Server Express Portable," Microsoft’s official answer is . LocalDB is a lightweight, on-demand, user-mode instance of SQL Server Express.

If the LocalDB workflow is still too reliant on host installation, consider these true portable databases that are not MS SQL Server:

Switch to SQLite to eliminate the need for a server engine entirely.

If you are looking for an official version that you can simply run from a USB drive without installation, the short answer is: it doesn't exist . Microsoft designs SQL Server as a service-based engine that requires deep integration with the Windows Registry and system services to function.