When using Spyder, everything works without problem.
I does not though in a virtual environment out of anaconda.
I created a virtual environment and installed pywin32 with pip.
I created a simple test script in Idle with just 1 line: import win32com .
It causes the error.
I checked the versions: all 64 bit. I use python version 3.7.4 and pywin32 version 225.
I ran the post install procedure, to no avail. To be sure I had the latest version of pywin32, I downloaded it from github.com/mhammond/pywin32/releases. I uninstalled Python and reinstalled it.
I have no solution in sight and no more inspiration.