Access 2013 uses the same file format as Access 2007 and Access 2010 for storing its databases, but previous versions of Access use a different format. You can tell what version a database is by opening it in Access and looking at the title bar. The title bar may display (Access 2000 file format) or (Access 2002-2003 file format) for an old format, or nothing or (Access 2007 - 2013) for the new format.
To convert a database from an older file format to the Access 2013/2010/2007 format, follow these steps:
Open the database.
Close any open objects.
Click the File tab of the Ribbon to enter Backstage View, and choose Save As.
In the Save As dialog box, below the Save Database As heading, select Access Database (*.accdb).
Click the Save As button.
Browse to the folder where you want to store the new version of your database.
Enter a name for the database.
Access creates a new database containing all the objects in the old database, stored in the new format, with the extension .accdb. Additionally, a message warns you that this new database can’t be opened in Access 2003 or earlier versions.
Click OK.