I've got Microsoft SQL Server EXPRESS and have a .mdf file (SQL file).

My question is; (1) how do I connect this .mdf file to the Express server so that I can connect to the server externaly elsewhere in the network from an IP adress?

Now I only can connect to the file if it's placed locally on my harddrive, but this database will be used from different computers in the network, and I want the server to handle all these connection.

(2) Also, the SQL server says the login/password is incorrect, how do I set the login/passord on the Express server ?