Access 2007 databases are considerably different from previous versions of Access. Due to the differences, Microsoft was unable to provide users of previous versions of Access with a compatibility tool. At this time, there is no way to convert an Access 2007 database into a format compatible with an earlier version of Access. However, Access 2007 can save databases in previous formats.
If you come across an Access 2007 database which you need to use, please contact the author of the database and have them save the database in an earlier format from within Access 2007. Detailed instructions on how they can do this are found at the link below.