Make sure to set the right environmental variables (https://github.com/conda/conda/issues/1744)
Create a new environment for 32bit Python 2.7:
set CONDA_FORCE_32BIT=1 conda create -n py27_32 python=2.7
set CONDA_FORCE_32BIT=1 activate py27_32
Create one for 64 bit Python 3.5:
set CONDA_FORCE_32BIT= conda create -n py35_64 python=3.5
set CONDA_FORCE_32BIT= activate py35_64
The best would be to write the activation commands in a batch file so that you have to type only one command and cannot forget to set the right 32/64 bit flag.
You don’t need to install a full Anaconda distribution for this. Miniconda is enough:
These Miniconda installers contain the conda package manager and Python. Once Miniconda is installed, you can use the conda command to install any other packages and create environments, etc. …
There are two variants of the installer: Miniconda is Python 2 based and Miniconda3 is Python 3 based. Note that the choice of which Miniconda is installed only affects the root environment. Regardless of which version of Miniconda you install, you can still install both Python 2.x and Python 3.x environments.
I would recommend you to use Miniconda3 64-bit as your root environment.
You can always install a full Anaconda later with:
conda install anaconda
Note that it might downgrade some of your previously install packages in your active environment.