Duplicate Preventer is a Business::Spreadsheets software developed by Nimble Software. After our trial and test, the software was found to be official, secure and free. Here is the official description for Duplicate Preventer: Duplicate Preventer is a Microsoft Excel add-in that helps to prevent entering duplicate data while working in Excel. Duplicate Preventer integrates into MS Excel by placing its toolbar into the Excel toolbar area. The add-in allows defining where to check for duplicates in the active row, column or only in a selected area. The duplicate tracking is optionally possible with exactly the same data and data within different letter cases. Defined tracking options save and activate in one click when required. you can download Duplicate Preventer 1.0 free now.