A partial installation can leave API sets in a state of limbo, where the registry expects a file that isn't physically present.
In the same Administrator Command Prompt, type: DISM /Online /Cleanup-Image /RestoreHealth . ext-ms-win-oobe-query-l1-1-0.dll missing
To prevent the "ext-ms-win-oobe-query-l1-1-0.dll missing" error from occurring in the future, follow these best practices: A partial installation can leave API sets in
If you are a developer, this error often occurs when a program tries to load a library (like libstdc++-6.dll ) that was compiled for a different environment or bitness (e.g., trying to load a 32-bit DLL into a 64-bit app). ext-ms-win-oobe-query-l1-1-0.dll missing
Sometimes, the error is not with Windows but with the application you are trying to run. The application might have a broken manifest that incorrectly calls for the OOBE API.