Create a helper Column B

In B2: =IF(COUNTIF($A$2:$A$100,A2)1,"Duplicated","OK")
Drag to copy as far as needed

Adjust to suit
AutoFilter the "OK"


"Doug C" wrote:

Please help! Excel newbie. How can I search a column of part numbers, finding
duplicates, and display part numbers are duplicated? I have played with
advanced filter, but can only seem to filter out the dulicates, not filter
out what is not duplicated.

Thanks