In Access 2007, when I create a new table, it defaults to an ID field that is autonumber. That is great and works as expected. When I create another field within the same table and want it to also autonumber, that is not a presented option when I try to format that field.

How do I set a second autonumber field within the same table?

You can't. There can be only one autonumber field in a table. You may not fully understand the purpose of an autonumber datatype. It has ONE and ONLY one purpose and that's to provide a unique identifier for a record. It is not a sequential numbering system.

If you explain what you want to use this second field for, maybe I can suggest an alternative.