I am using win32com in python to access a native C++ COM dll. I registered my COM component (SysWOW64/regsvr32 my.dll) and called makepy.py -i. In .py-code, I got the module and an instance from the class I need. Now when calling a method from this object I get an error in the auto-generated file from makepy: My function got enumerated, and in the generated file, there is the following statement: def MyFunction(self): 'method MyFunction' return self._oleobj_.InvokeTypes(14, LCID, 1, (24, 0), (),) So this is calling the actual COM method. But it fails: pywintypes.com_error: (-2147319779, 'Library not registered.', None, None) Do I need an additional registration? combrowse.py shows my object and the windows registry is okay. How should my dll be registered to be called by invoke?