Installation: Installed fine got password, cant login

This is my last attempt. I have installed the database on my yahoo server. I received my user name and password by email saying everything installed, but I can?t login with the user name and password. I even logged in to phpmyadmin and tried to change the password as I had read in the forum but that still didn?t help. I know I had to rename the 'localhost' to mysql to install, and I have even attempted the login with varied versions and I can?t login, it's killing me. Any solutions you can advise would be greatly appreciated, I would love to see how this works.