Excel: Find unique rows

Problem: Each row contains info in a consistent format and layout for a record in a database, with a unique ID in the first column.

Resolution: Assuming the data starts in cell A1, click in that cell and choose Format | Conditional Formatting from the menu. Change the drop-down to Formula is. Enter the formula =COUNTIF(A:A,A2)=1. Click the Format button, click the Pattern tab, and select a color, say, green. Click OK, OK. Now click the Format Painter button on the toolbar and highlight all the rest of the data in column A. Any ID that appears only once will now be green.

In Excel 2007, highlight all the cells in the unique ID column and click the big Conditional Formatting button on the ribbon. Select Highlight Cells Rules and choose Duplicate Values. In the little window that appears, change Duplicate to Unique and select the desired formatting.