i found some registry trees that store information for language/keyboard code
HKEY_LOCAL_MACHINE\Software\Classes\MIME\Database\Rfc1766
HKEY_LOCAL_MACHINE\System\ControlSet001\Control\Keyboard Layout\DosKeybCodes
HKEY_LOCAL_MACHINE\System\ControlSet001\Control\Nls\Locale
maybe removing those will clean a bit the selection menu at control panel -> region?
HKEY_LOCAL_MACHINE\Software\Classes\MIME\Database\Rfc1766
HKEY_LOCAL_MACHINE\System\ControlSet001\Control\Keyboard Layout\DosKeybCodes
HKEY_LOCAL_MACHINE\System\ControlSet001\Control\Nls\Locale
maybe removing those will clean a bit the selection menu at control panel -> region?