So worst case scenario - I move Data.fs, uninstall Plone/Zope, install plain vanilla Zope. Or keep running the Plone/Zope service from the commandline...
So it sounds like it works from the command line? Check the registry settings at HKLM/SYSTEM/CurrentControlSet/Services/Plone and make sure it all points to the Python contained in Plone. Check as well you have the most recent build of Plone. There was a minor bug in z2.py that could affect this.
Any way I could get a verbose Python-esque listing of what happens when the service is started?
Not really no, the system either starts in which case it logs to stupid log etc or it doesn't. You can start Python services through PythonService.exe in debug mode but it rarely helps, and you would have to read the documentation to make sure its correct. -- Andy McKay