Motor originally only integrated with Tornado, which did not officially support Windows due to concerns about "select" there.

Motor now integrates with asyncio, which does support Windows. Consider adding Windows to the tested and supported platforms for Motor with asyncio.

Tornado is about to release version 5, and deprecate Python 2. Tornado 6 or so will drop Python 2 and rely on asyncio's event loop. Once Tornado 6 is out, determine whether its Windows support is scalable enough to consider it a first-class Motor configuration.