No conection to your report
Open a new query, design view.
Add the table to the query, and list all the fields that you want to display
in the report.
Run the query, check how many records you have.
Now, In the menu bar select view > SQL.
You see
Select Field1,Field2,Field3 from TableName
Now add to the SQL
Select distinct Field1,Field2,Field3 from TableName
Run the query, check how many records returned.
If you have the same amount of records, it's mean that there are no
duplicates, if you have less records it mean that you eliminated the
duplicates.
Try it