Installation Wizard Issues

I can't get past the step 3. I get the error message telling me to have the correct server/hostname, username and password. I have spent considerable time trying to put in the right data. What exactly is the "server/host name"? Is that the web address without the www.? Do you put the username and password you use to log into your cPanel in those fields? I have contacted my web host (Hostgator) and they aren't that familiar with Powergallery. They couldn't help me. They said typically you use the web address without the www for the server/host name.

I have set up a new php database with username that is correct. That field is gray. The server/hostname, username and password fields are the ones that are red. I have set up a ticket here but haven't resolved the issue yet. I am very frustrated and want to get this fixed. Help?