I'm reasonably sure his point was that before you go messing with a
database, it's A Really Good Idea that you make a backup, just in case, for
example, something you do makes it where it doesn't work (and, unlike this
situation, you can't ever get it to work again).
It's also not a good idea, in fact A Really Bad Idea, to just delete from a
database anything unless you KNOW what it was supposed to do, and why it is
no longer needed.
It's A Good Idea to split your database into a front end (queries, forms,
reports, macros, and modules) and a separate back end (tables, the data in
the tables, and relationships) and link the front end to the back end using
the Linked Table Manager. That way, even if you manage to make an
irrecoverable mess of the front end (user interface), you have not lost all
the business data in the backend.
Larry Linson
Microsoft Office Access MVP