Question

I have windows autentication, if i should change how to change that???

 <add name="ConnectionString" 
      connectionString="Data Source=.\SQLEXPRESS;
            AttachDbFilename=|DataDirectory|\Database.mdf;
            Integrated Security=True;
            User Instance=True"
      providerName="System.Data.SqlClient" />


<authorization>
   <allow users="*" />
   <deny users="?" />
  </authorization>

Answer 1

Aspspider’s own instructions would be the best place to start.

How to create a new SQL Server database ? – it says here you can’t use auto attach, you have to attach it to the server via the Database Manager which I presume you have access to when you log into their management site.

And here are instructions on the connection string you should use:
Connection strings for MS Access and SQL Server Express