If you are trying to install it on a windows machine you need to have a 64-bit version of python 3.5. This is the only way to actually install it.
TensorFlow supports only 64-bit Python 3.5 on Windows. We have tested the pip packages with the following distributions of Python:
Python 3.5 from Anaconda
Python 3.5 from python.org.
You can download the proper version of python (make sure you grab one of the ones that says "Windows x86-64")
You should now be able to install with pip install tensorflow or python -m pip install tensorflow (make sure that you are using the right pip, from python3, if you have both python2 and python3 installed)
Remember to install Anaconda 3-5.2.0 as the latest version which is 3-5.3.0 have python version 3.7 which is not supported by Tensorflow.
Thank you,hope my answer will help you.