error while installing tensorflow in conda environment (CondaError: Cannot link a source that does not exist.)
Try to run conda clean --all --yes and conda update anaconda.
Do you have a conda.exe file in the following folder C:\ProgramData\Anaconda3\Scripts\?
Do you use the latest Conda?
Another solution could be to create a conda environments conda create -n name_environment pip python=3.5 and using pip to install tensorflow pip install tensorflow inside the new environment 
after having activated it (activate name_environment).
P.S. I can not write a comment because I do not have enough reputation.
EDIT - Now i can!
trying to install tensorflow using conda package manager
using following command

conda install -c conda-forge tensorflow

but it gives following error while executing transaction

CondaError: Cannot link a source that does not exist.
  C:\ProgramData\Anaconda3\Scripts\conda.exe