The easiest way to remove duplicate contacts in Outlook is by using Regain Outlook Duplicate Remover Tool. This efficient software automatically identifies and removes duplicate contacts, emails, calendars, and tasks from Outlook PST, OST, and BAK files. It supports all versions of Outlook and provides a user-friendly interface, making the process straightforward for even novice users. The tool scans across multiple PST files and folders to ensure all duplicates are removed. You can download a free trial version of the tool from Regain's official website to experience its features firsthand.