Your system has a lot of duplicate PST emails, and you can't remove them at once becouse of facing more errors. I have the best way, simply you can try TrustVare Outlook Duplicate Removal, it quickly scans duplicate PST files and removes them without losing your important data. This tool doesn't need MS Outlook or other applications; it supports all Windows OS versions like 11, 10, 8.1, 8, and 7. This software can handle a large number of duplicate PST files with 100% accuracy and consistency. Non-technical users can aslo use this software with technical skills.