Backup File = mydatabase.bak

1. Run Microsoft SQL Server Management Studio application.

2. If mydatabase is in Databases : delete mydatabase.

3. Right Click to Databases and select Restore Database ....

4.    Destination for restore -> To database: mydatabase

       Source for restore -> select From device -> Specify the backup media and select the backup sets to restore

       Select Options from Select a page and in Restore the database file as: type the fullpath for the mydatabase new location

(for initdb_Data line with .mdf extension and for initdb_Log line with .ldf extension 

ex.:

C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\mydatabase.mdf

C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Data\mydatabase.ldf).

5. Press OK button.

Have fun!