You can delete all data in the table, then Tools, Database Utilities, Compact and Repair. This may set the first record Autonumber to 1. Be aware that autonumber is usually used for a primary key (unique value) in a table. If this is the case, it doesn't matter what value the autonumber is.

 

However, if it does not work, there is another way, viewable << here >>

Method #1 worked perfect.  Thank you Allan!

If you really need to have the first record start at 0, you can create a new field, say "NEW_ID", and make an expression Auto_ID - 1 in an update query.