If you have a .bak file, and all you want is to restore that file to a mdf. Then this is what you can do. It's a little hacky but works.
First you need an empty .mdf and .ldf files. The easier way to do that is to create a Web Project in Visual Studio and then In the App_Data folder right click and add new database. That will create an mdf and a .ldf.
Now copy those files to the data directory of your SQLSERVER Express. If it usually under the C:\Program Files\Microsoft SQL Server. In my case it is in C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\
So if your database is PhoneBook just copy:
copy PhoneBook.mdf “C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\PhoneBook.mdf”
copy PhoneBook_log.ldf “C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\PhoneBook_log.ldf”
Now attach your database:
open a Visual Studio 2008 Command Prompt or other prompt (Remember to right click the Run as Administrator, specially if it is Vista)
in the command prompt run:
sqlcmd –S ./SQLEXPRESS
and run the following commands:
CREATE DATABASE Phonebook ON
( FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Phonebook.mdf' ),
( FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Phonebook_log.ldf' )
FOR ATTACH ;
copy your .BAK file to the data directory.
copy PhoneBook.bak “C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\PhoneBook.bak”
NOTE: Why the data directory: It seems that in some installation you can have permission issues
RESTORE DATABASE PhoneBook
FROM DISK = 'C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\PhoneBook2.BAK'
WITH MOVE 'Phonebook' TO 'C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Phonebook.mdf',
MOVE 'Phonebook_log' TO 'C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\Phonebook_log.ldf',
After that if everything runs ok then you can detach your database:
exec sp_detach_db 'Phonebook'
Now you can copy your mdf files back to where you wanted them
NOTE: If you don't know the name you have to put for Data and Log then Run commands like
`RESTORE HEADERONLY FROM DISK ='C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\PhoneBook2.BAK'
RESTORE FILELISTONLY FROM DISK ='C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\PhoneBook2.BAK'`
Hope this helps