You will need to set up a separate backup device for the FULL and the DIFF. When you create the Backup Device it is a single file. You can't save a FULL and a DIFF in the same Backup Device.
More information about backup devices can be found here: http://msdn.microsoft.com/en-us/library/ms179313.aspx
If you are trying to restore the database over an existing database and want to replace the data you will need to use the WITH REPLACE option in the restore. More information can be found here: http://msdn.microsoft.com/en-us/library/ms186858.aspx
REPLACE should be used rarely and only after careful consideration.
Restore normally prevents accidentally overwriting a database with a
different database. If the database specified in a RESTORE statement
already exists on the current server and the specified database family
GUID differs from the database family GUID recorded in the backup set,
the database is not restored. This is an important safeguard.
The REPLACE option overrides several important safety checks that
restore normally performs. The overridden checks are as follows:
Restoring over an existing database with a backup taken of another
database.
With the REPLACE option, restore allows you to overwrite an existing
database with whatever database is in the backup set, even if the
specified database name differs from the database name recorded in the
backup set. This can result in accidentally overwriting a database by
a different database.
Restoring over a database using the full or bulk-logged recovery model
where a tail-log backup has not been taken and the STOPAT option is
not used.
With the REPLACE option, you can lose committed work, because the log
written most recently has not been backed up.
Overwriting existing files.
For example, a mistake could allow overwriting files of the wrong
type, such as .xls files, or that are being used by another database
that is not online. Arbitrary data loss is possible if existing files
are overwritten, although the restored database is complete.
There are couple of things to consider :
backup and restore is the safest option that you can use for migration from SQL 2005 to 2012.
Refer here for more details of what you are experiencing.
Full text has undergone major chance in 2008 and up.
from BOL,
Attaching a SQL Server 2005 Database to SQL Server 2012
In SQL Server 2008 and later versions, a full-text catalog is a logical concept that refers to a group of full-text indexes. The full-text catalog is a virtual object that does not belong to any filegroup. However, when you attach a SQL Server 2005 database that contains full-text catalog files onto a SQL Server 2012 server instance, the catalog files are attached from their previous location along with the other database files, the same as in SQL Server 2005.
The state of each attached full-text catalog on SQL Server 2012 is the same as when the database was detached from SQL Server 2005. If any full-text index population was suspended by the detach operation, the population is resumed on SQL Server 2012, and the full-text index becomes available for full-text search.
If SQL Server 2012 cannot find a full-text catalog file or if the full-text file was moved during the attach operation without specifying a new location, the behavior depends on the selected full-text upgrade option. If the full-text upgrade option is Import or Rebuild, the attached full-text catalog is rebuilt. If the full-text upgrade option is Reset, the attached full-text catalog is reset.
EDIT:
You can attach the detached database along with the fulltext catalog using Create database ... FOR ATTACH.
-- Physically move the full text catalog to the new location.
--Attach the AdventureWorks database and specify the new location of the full-text catalog.
CREATE DATABASE AdventureWorks ON
(FILENAME = 'D:\...\Data\AdventureWorks_Data.mdf'),
(FILENAME = 'D:\...\log\AdventureWorks_log.ldf'),
(FILENAME = 'D:\myFTCatalogs\AdvWksFtCat')
FOR ATTACH;
GO
Best Answer
Try to do this with T-SQL: