Attach DB in SQL Express

Here is what my connection string looks like (the private information is changed):

"Data Source="MACHINENAME\\SQLEXPRESS";User ID="Admin";Password="the_password";InitialCatalog="MyDatabase";Integrated Security=True";

if this is not work try this link..!
http://stackoverflow.com/questions/997169/c-sharp-2008-sql-server-express-connection-string[^]

http://www.connectionstrings.com/[^]

Dear Ben,

To attach a database

In SQL Server Management Studio Object Explorer, connect to an instance of the Microsoft SQL Server Database Engine, and then expand that instance.

Right-click Databases and click Attach.

In the Attach Databases dialog box, to specify the database to be attached, click Add; and in the Locate Database Files dialog box, select the disk drive where the database resides and expand the directory tree to find and select the .mdf file of the database; for example:

C:\Program Files\Microsoft SQL Server\MSSQL10_50.MSSQLSERVER\MSSQL\DATA\AdventureWorks2008R2_Data.mdf


Optionally, to specify a different name for the database to attach as, enter the name in the Attach as column of the Attach Databases dialog box.

Optionally, change the owner of the database by selecting a different entry in the Owner column.

When you are ready to attach the database, click OK.

Note: A newly attached database is not displayed in the Databases node of Object Explorer until the view is refreshed. To refresh the view at any time, click in Object Explorer, and then click Refresh on the View menu.

Regards,
Bluesathish