The Windows build actually uses the registry to locate the standard library rather than sys.path. This is by design, but isn't really documented properly.

It means that code on sys.path (even in the current directory) won't shadow standard library modules on Windows.

Due to various arcane details about how it is implemented, the emulation of the main import system that is used to run code with the '-m' switch gets the search order the other way around and hence gives a different answer (the same answer as Linux) in cases like this.