I was working on a database and it was autonumbering just fine. when i went to open it up the autonumbering was disabled. how do i turn that fuction back on?? I have tried changing the data field from number to autonumber and i get a error message that reads: Once you entered data in a table, you can not change the datat type of any field to autonumber even if you haven't yet added data to that field. Add a new field to the table, and define its data type as autonumber Microsoft office access then enters data in the autonumber field automatically, numbering the recordsconsecutively starting with 1.