BCDBOOT - Create or repair a system partition - Windows CMD Commands

SyntaxBCDBOOT source [/l locale] [/s volume-letter][/v] [/m [{OS Loader GUID}]]
Optionssource  The location of the Windows directory to use as the source for           copying boot-environment files.
   /l      The locale. default = US English.
   /s      The volume letter of the system partition.           The default is the system partition identified by the firmware.
   /v      Enable verbose mode
   /m      By default, merge only global objects.           If an OS Loader GUID is specified, merge the given loader object within           the system template to produce a bootable entry.
BCDboot may also be run from Windows PE (Preinstallation Environment)
Examples
Initialize the system partition using files from the operating system image installed on the C: volume:
C:\> bcdboot C:\Windows
Set the default BCD locale to Japanese, and copy BCD (Boot Configuration Data) files to drive S:
C:\> bcdboot C:\Windows /l ja-jp /s S:
Merge the OS loader in the current BCD store identified with the given GUID in the new BCD store:
C:\> bcdboot c:\windows /m {d58d10c6-df53-11dc-878f-00064f4f4e08}