If you have already programmed a bit in OLE/ActiveX/Shell extensions/etc. in the Microsoft world, you already know the RegSvr32 command used to register/unregister these dll components. The regsvr32.exe command only calls the DllRegisterServer entry point, i.e. a method with that name located in the DLL. Typically, but not limited to, this method creates keys (nodes and leaves) in order to register the component inside the Windows registry.
Now, let’s say you have an ActiveX component and you want to see the keys it would create when self-registering, but for some reason you don’t want to actually install it on your computer. Visual Studio has a tool that is extremely convenient for this. It is called Registry Capture (regcap.exe). You can launch it on your dll component in order to generate a reg file containing the registry keys:
regcap /O output_file.reg activex.dll