Registering the Marshalling Code
If you are using type-library marshalling then you need only register the type-library. A simple way to achieve this is to use Dolphin's Active-X Component Wizard to browse for and open the type library. If you used the wizard to generate interface wrappers from the type library during development of the component, then this will already be done and you need take no further action.
If you are using standard marshalling code (e.g. when implementing interfaces with argument types that are not automation compatible) then it will be necessary to build and register a separate marshalling DLL. This is relatively straightforward, but is an advanced topic that should be avoided initially.