Yes, there are many simple ways to remove duplicate items from multiple PST files. You can try the perfect solution for it I'm also using so you can use it. Try the TrustVare Outlook Duplicate Remover, which can find duplicate items in the PST files and remove them without any issues. It will handle a large number of duplicate PST files without downloading MS Outlook files. The software supports all Windows OS versions like 11, 10, 8.1, 8, and 7. You can use their free demo versions before buying the full edition. It will give you a preview option before deleting duplicate PST items.