Problem installing VTKPython

[Enrique]

Hi,
I am trying to check the visualization program MayaVi, a
python application that uses VTK and VTKpython. 
I work in a MS-Windows PC
I have downloaded VTKcore.exe and VTKPython.exe.
Installation of VTKcore.exe simply copies vtkdll.dll into
c:\windows\system.

When I try any script in VTK python I get a message
complaining about a missing DLL: vtkpython. I have
vtkpython.dll in the DLLs folder of python installation, and
in the vtkpython folder. However I cannot import vtkpython,
the error message is:

Python 2.1.1 (#20, Jul 20 2001, 01:19:29) [MSC 32 bit
(Intel)] on win32
Type "copyright", "credits" or "license" for more
information.
>>> import vtkpython
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
ImportError: DLL load failed: One of the library files
needed to run this applic
ation cannot be found.

I am missing something, but I do not know what
TIA
Enrique