i have done all the settings like it is discribed in "OCS in an hour". But there is no possbility to register to the conference ("Registration" is not shown in the menu bar)!
Check the publication date for registration is active for now.
Check that you have configured the registration options.
Sometimes to see the changes you have to empty the system cache / template cache
And the second questions is if it´s possible to register for the conference as an unregistered user?
The only way to register a presenter would be for the admins to do it from within the admin section. There is no way that I have seen whereby a visitor can register for a conference if he/she isn't already a registered user.