Finding Duplicates

Hello,
I'm trying to identify duplicates between two spreadsheets. Excel 1 is a single spreadsheet. Excel 2 is a Workbook. I need to make sure entries in Excel 1 don't also appear anywhere in the Excel 2 Workbook. Not sure how to proceed.

Well, at least you can SEE what your data looks like. We can't, so we have no idea what type of data you are talking about - dates, names, ID numbers ??

Please attach sample Excel files by following the instructions given in the yellow banner at the top of the screen.

Pete

My apologies. Both Excel Files contain a column with a Project Number. That Project Number is a combo alpha/numeric and is 7 characters. I just need to make sure I'm not duplicating efforts.