The current C1DynamicHelp control will use the MainControl's properties: HelpSource, Resolver, Provider, etc instead of its own properties. It is used to place C1DynamicHelp controls on multiple forms that will display topics from one help source. In this case you will have one main C1DynamicHelp control and set properties for it, and all you need to do for the other C1DynamicHelp controls is to set their MainControl property to the main C1DynamicHelp control.