Remove/Delete Duplicate Values From Your Data

1) From the Data tab, in the Data Tools group, click Remove Duplicates;

2) In the Remove Duplicates dialog, all columns are selected by default. This means that if there are rows with identical values in all columns, duplicate rows subsequent to the first instance are removed from the Table or selection.

To remove duplicate records for rows where only certain columns contain duplicate values, uncheck the columns you don't want to check for duplicates. If your data contains a lot of columns and you want to select only a few columns, you may find it easier to click the Unselect All button first and then select only those columns;

3) Click OK. A message will be displayed indicating how many duplicate values were removed and how many unique values remain. 

Note that at this point you do have the option to Undo the Remove Duplicates action.

Also note that you use this Remove Duplicates feature on data that contains subtotals or is outlined. You will have to remove the subtotals and outlines first.