In Access 2010, you will a lot of Table Tools to let user change table fields settings. Since data type has to be specified for each field, it also allows user to change the data type on the fly without opening database in design mode. Let’s see how to change the data type of an existing field.
For changing the Field’s data type, select the field by clicking column title and head over to Table Tools Fields tab. From Formatting group, under Data Type option, select a data type for the selected field.