[Vadikan]

lmn
Я справку процитирую к MUI

/i (specifies the user interface language(s) to be installed) /d (specifies the default user interface language that will be applied to all new user accounts) /l (matches the language of non-Unicode programs with the default user language; this setting is ignored unless /d is set) /f (matches the default shell user interface font with the default user language; this setting is ignored unless /d and /l are set) /u (specifies the user interface language(s) to be uninstalled; uninstalls all installed languages if no language is specified) /r (specifies that the reboot message should not be displayed) /s (specifies that no messages will be displayed during installation)

Очевидно, у тебя не хватает ключа l. Вот с какими ключами я ставил из cmdlines.txt

Код:

".\WinMUI\Muisetup.exe /i 0419 /d 0419 /l /f /r /s"

чтобы при загрузке войти уже в русский интерфейс и иметь российские регион. настройки.