If you are running Windows 10, you can optionally install the Ubuntu Bash Shell (Currently Ubuntu 14.04) - See the MSDN page for details and installation instructions. Once installed, the following commands can be used to install the OpenStack CLI client:
While potentially you can input your user credentials on the command line every time you run openstack, the simpler (and more secure) option is to put your credentials into a file which you read from before using the CLI. First log in to the Nimbus dashboard, where you can download your Nimbus credentials file by clicking on your username in the top right corner and selecting "OpenStack RC File v3" (save it as something like nimbus-rc).
Once created, you can load your credentials by running:
Running your Nimbus credentials file will prompt you to input your Pawsey account password (NOTE: be aware that your password will then be available in plaintext in the environment variable OS_PASSWORD, until you either log out or unset that variable).