How to Eliminate Records with Excel 2013’s Eliminate Duplicates Feature
Click the Remove Duplicates command button on the Ribbon’s Data tab or press Alt+AM.
Excel selects all the cells in the data list while at the same time displaying the Remove Duplicates dialog box.
When this dialog box first opens, Excel automatically selects all the fields in the list (by placing check marks in the check boxes in front of their names in the Columns list box). When all the fields are selected and you click OK in this dialog box, Excel deletes only complete duplicates (in other words, copies) of the records in the list.
If you want the program to remove records where there’s any duplication of entries in particular fields (such as the ID No field), you remove the check marks from all the columns except for those whose duplication are sufficient reason for deleting the entire record (as described in Step 3). Otherwise, you proceed directly to Step 4.