.. blogpost::
    :title: Cannot import DLL
    :keywords: numpy, scipy, scikit-learn, DLL
    :date: 2015-10-01
    :categories: import, module, issue

    I just tried::

        import scipy
        import scipy.stats

    But it failed with an error::

        DLL load failed

    The error happened again when using *scikit-learn*.
    As both modules are using *numpy*, I suspected than
    this one was not properly installed. It usually happens
    on Windows when you upgrade a module which takes a dependency on it::

        pip install <module> --upgrade

    *pip* notices that *numpy* has to be updated.
    Unfortunately, many modules only accepts the MKL compilation
    available here:
    `Unofficial Windows Binaries for Python Extension Packages <http://www.lfd.uci.edu/~gohlke/pythonlibs/#numpy>`_::

        pip uninstall numpy
        pymy_install3 numpy