Where does WinSCP save the "Configuration storage" settings?

I wonder where the settings for "Configuration storage" in the Preferences\Storage menu of WinSCP are saved. The setting specifies whether the WinSCP configuration is stored in the Windows registry or in an INI file.

I checked the WinSCP registry keys and the cofiguration file that can be exported. I did not find anything regarding this setting.

So where is this setting saved? I need to set it from INI file to Registry on serveral systems. This must be done as a default for all users.

I have added as answer to configuration:
https://winscp.net/eng/docs/config#auto