if the number in the first column matches will the data in the other two
columns be identical.
if not
when they combine do you want the information in one sheet to override the
other sheet or do you want the final product to show the information from
both sheets in the same line. in separate cells or combined in one cell.

one method to do it if all of the information is identical in each worksheet
is to in sheet 2 use
in D1
=countif('Sheet1'!A:A,A1)
copy down to the end of the data
use autofilter to select all the zeros and copy thes and paste at the end of
the data in sheet 1.

"Myles" wrote:

I am dealing with 2 Workbooks that have about 40,000 rows each, so it is way
too much work to combine, and edit them by hand. I have numbers in the 1st
column, 2nd i have Text, and 3rd I have Numbers. One File only has the first
2 columns. I need my other file to be combined w/ this one. The other file
has all 3 columns, but a lot of numbers in the 1st column should match each
other. So i want them to combine, but have no duplicate numbers. Can anyone
help me? thanks