I am trying to compare, two huge outputs from different databases. I have
combined them on the same worksheet, with one being highlighted. I am now in
the process of adding a conditional format to all the cells. I have two
conditional formats, each specific to the row.
So, I select and highlight two rows at once.
Then I copy the rows.
Then I select the rows I want to past3 to.
Then I right-click and paste special -- formats, Skip blanks -- OK.

At this point I get the following message "Selection too large"

When I reduce the number of row I select for pasting to, then it work for a
little while. Eventually, I get the same error message. And I once again must
reduce the number of rows I past at any one time.

Please, let me know what I am doing wrong, or please point the right
document in the MS knowledge base.

Do you mean copying and pasting columns?

Can you provide an example of what you are comparing?