*.mdf is not a database, it is database file used by SQL Server/Express. It
can only be accessed by SQL Server server, nothing else. You do not add
password to it (there is not way to do it antway). You need to learn how to
install/configure SQL Server server instead. I strongly suggest do some
study on SQL Server before you go ahead with using SQL Server membership
provider in your ASP.NET web site/app.
> can i add a username and password to access ASPNET.MDF for the purpose
> of security.. if we can add username and password for it.. how to use
> the Login controls to access that database..