If you want to enforce user's to go through a full registration, you just need to disable those custom fields from appearing under the mini registration view.

Thanks for reply,
in custom field the field "Joomla User Fullname" don't show "Appear in Mini Registration" options in "View" tab and i can't disable it from appearing under mini registration view.

Why?

Hello Alessandro,

Hm, actually there's an easier way. Just go to your theme settings, Themes > [Click on the theme you are using] > Dashboard , there's an option for "Display Mini Registration". Just turn this option off

Thank you for support,
problem solved with "Display Mini Registration" turned off.

Hello Alessandro,

You're welcome.