Localhost everytime redirects to 127.0.0.1 and can only access from your maschine, not over the web. If you want to use a real domain you have to edit the Binding and add a domain e.g. www.domain.com and domain.com on your IIS. Also you have to add thise domains to the alternate mapping into your portal settings you can find on Admin or system in your DNN instance.

Most times the SQL Server by a hoster is not local and used SQL login instead of Windows security about the SQL server is on a 2nd Maschine and not on an Active Directory Domain Controller! This means you have to setup a SQL user to your SQL Server, bind this user for use to your database as dbowner with standard schema dbo.

AttachDbFilename=|DataDirectory|Database.mdf means the data are in a file database you can find in your DNN root path\App_Data folder. Of cause using the Windows login security here you need a local SQL Server (Express) and you must have set the right permissions for access!

Example for SQL Server Login:

< add name="SiteSqlServer" connectionString="Server=sql.hoster.com;Database=DotNetNuke;uid=username_here;pwd=password_here;" providerName="System.Data.SqlClient" >< /add >