After enabling Insider and installing Python3.7 from the Windows Store, I open a cmd window and do `pip install --user numpy` which runs to completion. But I cannot `import numpy`. 

The NumPy `mutiarray` c-extension module in the `numpy/core` directory depends on an `OpenBLAS` DLL that is installed into the `numpy/.libs` directory. But even after adding that directory to the `PATH` before running python (and checking with `depends.exe` that the `multiarray` c-extension module is now not missing any dependencies) I still cannot `import numpy`.

See also NumPy issue https://github.com/numpy/numpy/issues/12667