RegObj.dll is an ActiveX server--and, hence, has an automation interface--that is available with documentation in the distribution file known as RegObji.exe, from the following page: http://msdn.microsoft.com/vbasic/downloads/addins.asp To provide early binding for RegObj use >>> from win32com.client import gencache >>> gencache.EnsureModule('{DE10C540-810E-11CF-BBE7-444553540000}', 0, 1, 0) or the MakePy utility within PythonWin, referring to "Regstration Manipulation Classes (1.0)" (Please notice the spelling error.) Sample use, to determine what command is associated with a Python file: >>> from win32com.client import Dispatch, gencache >>> from win32con import HKEY_CLASSES_ROOT >>> gencache.EnsureModule('{DE10C540-810E-11CF-BBE7-444553540000}', 0, 1, 0) >>> regobj = Dispatch ( 'RegObj.Registry' ) >>> HKCR = regobj.RegKeyFromHKey ( HKEY_CLASSES_ROOT ) >>> PythonFileKey = HKCR.ParseKeyName('Python.File\Shell\Open\command') >>> PythonFileKey.Value u'J:\\Python22\\pythonw.exe "%1" %*'