Tensorflow for Poets | Relaunching Docker | invalid reference format

I'm a beginner, trying out Tensorflow for Poets. I have been following instructions to build my own image classifier. But I get an error while following Step 3 of the tutorial at here

When I run the following command in PowerShell:

docker run -it \ --publish 6006:6006 \ --volume ${HOME}/tf_files:/tf_files \ --workdir /tf_files \
tensorflow/tensorflow:1.1.0 bash

I get the following error:

C:\Program Files\Docker\Docker\Resources\bin\docker.exe: invalid reference format. See 'C:\Program Files\Docker\Docker\Resources\bin\docker.exe run --help'

I have tried passing home address instead of $HOME, tried even lower case for the address. But still I get the same error.

I'd appreciate thoughts and suggestions.

Thanks!