What error do you get when you run the append query? It could be that the
file size is nearing the 2 GB limit. First make a backup copy of the database
then run a compact and repair. Then try the append query ideas.

Nobody would suggest copying and pasting ten rows, much less 470000.

Copy and paste the *STRUCTURE* of the table - not the table. Select the table
in the tables window; type Ctrl-C to copy and Ctrl-V to paste. You'll get a
popup window offering three choices - Structure Only, Structure and Data, and
Add records to existing table. Check Structure Only.

You'll then be asked for a new table name. Open this new table, and set a
unique Index on the combination of fields which identify a duplicate.

Compact the database at this point to be sure it's starting clean.

Then create a new Query based on the original table. Change it to an Append
query and select the new table. Run the query using the ! icon; you'll get a
warning message "25236 records were not appended due to key violations" -
that's the duplicates you're trying to get rid of.

            John W. Vinson [MVP]

Provided the table has a column (or columns) with unique values, e.g. an
autonumber, it can be done with a DELETE query.  Say the duplicates are
identified by LastName and FirstName columns (unrealistic of course as names
can legitimately be duplicated) and the unique values are in a column YourID:

DELETE *
FROM YourTable As T1
WHERE EXISTS
  (SELECT *
   FROM YourTable As T2
   WHERE T2.LastName = T1.LastName
   AND T2.FirstName = T1.FirstName)
AND YourID >
   (SELECT MIN(YourID)
    FROM YourTable As T3
    WHERE T3.LastName = T1.LastName
    AND T3.FirstName = T1.FirstName);

Ken Sheridan
Stafford, England