how do I compare two data files for duplicate entries in Excel

[Trevor Shuttleworth]

I think you're going to provide a little more information.

 

[CLR]

I use Jim Cone's fine commercial Add-in called XL Companion. It will do
that and a whole lot more. It's available at

http://www.realezsites.com/bus/primitivesoftware/index.php

Vaya con Dios,
Chuck, CABGx3