Problem setting up WP Multisite

I’m running into issues setting up multisite on my new word press install. I’m using HostGator. On HostGator I have two directories, public_html and root www. When I make the change to the config file and replace it in the www root directory the network option shows up in the tools section of the dashboard. When I replace it in the public_html folder it doesn’t. The second step fails both ways. Could you guys help me out with this?