How to Find Duplicate Cell Content on Excel 2003

1. Place the cursor in cell A1 (or the first cell where you want to test for duplicates). Click the 'Format' menu and then click 'Conditional Formatting.' Click the down-arrow in the box under 'Condition 1' and select 'Formula Is.' Enter the following formula into the text box to the right of 'Formula Is.'=COUNTIF(A:A,A1) > 1
2. Click the 'Format...' button on the right side of the window. Click the 'Patterns' tab and select an easy-to-find color such as red or yellow. Click 'OK.'
3. Click the 'Edit' menu with the cursor still in the cell where you entered the formula and select 'Copy.' Press and hold 'Ctrl' and then press the spacebar at the same time to select the entire column. Click the 'Edit' menu again and select 'Paste Special.' Choose the 'Formats' option in the Paste Special dialog and click 'OK.' Any duplicates found in the column will be highlighted with the selected color.