"GARY" wrote in message
...
COL A has 800,000 cells
COL B has 750,000 cells

Here's an example of my spreadsheet:

A B
008101966-1 008101966-1
008101968-3 008101968-3
008101969-4 008101979-3
008101970-4 008101968-3
008101979-3 008101979-3
008101981-4 008101981-4
008102023-2 008102023-2
008102025-4 008102025-4
008102028-7 008102023-2
008102030-8 008102025-4
008102313-4 008102319-0
008102314-5 008102368-4
008102319-0 008102369-5
008102368-4 008102402-1
008102369-5 008102404-3
008102402-1 008102417-5
008102404-3 008102418-6
008102417-5 008102437-3
008102418-6 008102438-4
008102437-3 008102443-8
008102438-4 008102455-9
008102439-5 008102464-7
008102443-8 008102465-8
008102455-9 008102466-9
008102464-7 008102535-8
008102465-8 008102548-0
008102466-9 008102561-1
008102482-3 008102562-2
008102485-6
008102535-8
008102548-0

In Excel 2007, I how do I find the cells in COL B that do NOT match
the cells in COL A?

I'd use conditional formatting. Select a cell in column B, say B2, and set
conditional formatting so that say it has a red background (pattern) if it
does not equal A2. Then copy the formatting of B2 to the whole B column
using the format painter (click on the column head).

V