/Set-InputLocale:{ | : } Sets the input locales and keyboard layouts to use in the mounted offline image. This command is ...

/Set-InputLocale:{ | :} 

  Sets the input locales and keyboard layouts to use in the mounted offline
  image.
  This command is not supported against an online image.

    Examples:
      DISM.exe /Image:C:	est\offline /Set-InputLocale:en-US 
      DISM.exe /Image:C:	est\offline /Set-InputLocale:0409:00000409