ActiveX controls need to be registered in the computers registry in a few key locations to allow for the proper instantiation and type library binding.

It is possible that depending on the location of the controls and the nature of your application that the programming engine registered them for you.

Technically, the registration process for a control is to either use RegSvr32 or load the library into memory then using a function pointer Invoke the DLLRegisterServer function to cause the control to create the appropriate registry entries.

It is best practice to ALWAYS register the controls on the machine and to place those controls in the SYSTEM directory on the target machine to avoid version conflicts.