This command enables or disables the boot debugger for the specified boot entry. Although this command works for any entry, ...

This command enables or disables the boot debugger for the specified boot
entry. Although this command works for any entry, it is only effective for boot
applications.

bcdedit /bootdebug [] { ON | OFF }

        Specifies the identifier of the entry to be modified.
            For information about identifiers, run "bcdedit /? ID".

Examples:

The following command enables boot debugging for the Windows operating system
loader of the current operating system boot entry:

    bcdedit /bootdebug ON

The following command disables boot debugging for the Windows boot manager:

    bcdedit /bootdebug {bootmgr} OFF