You have a lot of duplicate PST files, and you want to delete them without losing data. I can suggest that if you have many duplicate PST emails, you can try "TrustVare Outlook Duplicate Removal." It will scan duplicate PST emails and remove duplicate emails without error. There is support for large duplicate PST files, removing emails without impacting original data. This software supports all Windows OS versions, like 11, 10, 8.1, 8, and 7. It doesn't matter if you have any technical skills or not, as you can use this software without any technical abilities and delete multiple duplicate PST files. You can use their free demo version.