Take care when you are closing open windows, if you close the Database window, you will close the whole database. Access saves data as you enter it, so you will not lose any work. And if you have been working on defining an object, Access will check with you about saving changes before closing. If you do accidentally close the database, just open it up again and continue working.

Access 2010 and 2007 introduced a multitude of new features available to both the MDB and ACCDB^[1] file formats. When working with multiple versions of Access, it can be confusing to keep track of what will work for each version. The following table lists the new features and how they will behave in prior versions of Access. New features for Access 2007 or 2010 MDB fi les are also available for ACCDB fi les, but the reverse is not always true. Features that are available for ACCDB files but not for 2007 or 2010 MDB files are denoted by the statement
"Not available to MDB fi les; only available in ACCDB fi le format."

[1] ACCDB file formats: Many Access databases contain hundreds or even thousands of tables, forms, queries, reports, macros, and modules. With a few exceptions, all the objects in an Access 2016 database reside within a single file with an extension of ACCDB or ACCDE. Access databases can also have an extension of MDB or MDE. Databases with these extensions are backward-compatible with Access 2003 and prior versions.