I had definitely tried that earlier but for some reason it wasn't working. However, thanks to your response I took another look at my configuration to see why that particular install package wasn't running properly.
I originally used Anaconda to install a dual Python 2.7/3.5 environment and while I was always able to run 3.5 without any issues in an IDE (Jupyter Notebook in this instance), the current environment had still automatically defaulted to 2.7. The quick way to check for this via the command window is:
C:\Users\Username\Anaconda\envs>conda env list
which should produce something like:
# conda environments:
#
py27 * C:\Users\Username\Anaconda\envs\py27
py35 C:\Users\Username\Anaconda\envs\py35
Note that there will be '*' next to the environment that is currently active. To switch, simply type 'activate' followed by the new desired environment name and the change should immediately be verified by the command prompt that is returned:
C:\Users\Username\Anaconda\envs>activate py35
(py35) C:\Users\Username\Anaconda\envs>
After making the environment change, I reran the conda install package for pydotplus that you mentioned:
conda install -c conda-forge pydotplus
and it worked perfectly!
Two other quick things to consider when installing pydotplus to ensure that it interacts correctly with GraphViz in your particular environment:
Make sure you're running the most up to date version of scikit-learn. More info is provided on the official website (http://scikit-learn.org/stable/install.html), including the quick update command: conda update scikit-learn
Verify that the GraphViz bin directory has been added to your User Path: (Why is pydot unable to find GraphViz's executables in Windows 8?)