Uninstall any version of Java before starting. Previous installations of Java might conflict with the Calabash setup.
Download and install Java JDK SE Edition. It is preferred to not install in Program Files, put it in C:\Java (or another directory with space)
Click the download button for Java JDK and download the installer based on your system specs.
By default the installer wants to install in Program Files. Click the button 'Change' and create a new folder called Java followed by the version number.
Install in your newly created folder.