when you put in your database information did you use a prefix on username and db name, it should be format such as prefex_name the prefex is your username u use to sign in... For example if you use cPANEL then it would be your username for cpanel.
So if that is the case.. then do it like this
cPanelname_dbname
cPanelname_dbusername
you do not need to use the prefix for the password just put the password by itself. Also use for the host type in the word localhost..
does that help...