There is a discussion with some insight into the technical reasons why they don't support Windows 7: https://discuss.python.org/t/windows-7-support-for-python-3-... (summary: api-ms-win-core-path-l1-1-0.dll is not available on Windows 7, so they'd have to switch from static import to feature detection + dynamic import in several places; and the Python team don't have access to Windows 7 so they can't do testing).

An unofficial Python installer for Windows 7 exists: https://github.com/adang1345/PythonWin7 (it uses an unofficial implementation of api-ms-win-core-path-l1-1-0.dll).

Thanks for that insight. The part about not being able to do testing doesn't surprise me, it's to be expected.

Windows 7 support ended on 14 Jan 2020. It makes sense not to officially support it.

Have you tried building 3.9 from source to see if there's a particular API that's unsupported?

Sure, I wouldn't expect to get any help from the Python folks if I had some trouble. I was hoping for more of a don't care philosophy. But the installer goes out of its way to disallow installing it.

No, I haven't tried to build from source. That's a rabbit hole I'm not particularly interested in jumping down.

These might be interesting to you: https://github.com/indygreg/python-build-standalone/releases