Removing duplicates

I just finished a more or less the same job.
I tried two approaches but finally I used the easied one.

1. FIRST SOLUTION.
Place the worksheet function to determine the double entries. The COUNTIF takes a cell value and look if this appears in a range. If there is 1 or more appearance he set D (Duplicate) in a Column.

range1 = "D3:D" & LastRow
Sheet20.Range("A3:A" & LastRow).Formula = "=IF(COUNTIF(" & range1 & ",D3)>1,""D"",""F"")"

With a short IIF you delete the D's for example.

2. SECOND SOLUTION :
A complete sub or function dat delete every double without writing the COUNTIF function to you sheet.

If you want some more explanation or feedback or code, ask ....