Thanks Chris M and handrawn. In fact, I went through the process you describe long ago. English is set as my preferred language. The time and date, along with certain Windows commands, are displayed in English. The operating system, itself, however is not affected by that. It remains in Spanish. As an example, if I right-click the Windows key, I am shown options in Spanish, like 'Aplicaciones y características' and 'Configuración', instead of 'Applications' and 'Settings'. Default file folders remain 'Descargas' instead of 'Downloads' and 'Documentos' instead of 'Documents'. If you try to rename them, they return to the default. Even 'Shut down' remains as 'Apagar'. In other words, changing the preferred language doesn't change the system language, only the superficial display of certain items.