You can also try the KDETools PST Merge to merge archived PST files in MS-Outlook in any Version of Windows and Outlook. It Combines PST files without any duplicates PST items. It Consolidates various PST files such as Emails, Contacts, Calendars, Tasks, Notes and all. It merges without any duplicates PST files in MS-Outlook. Demo Version is also available. Preview option is available to check before merging process. Supports in all Version of Windows and Outlook. Capable in ANSI and also UNICODE formats.
More Info: https://www.kdetools.com/pst-merge.html
if you want to merge your multiple PST files into a single one, then use the fastest and safest Merge Outlook PST Tool, which can easily combine your multiple PST files into a single one without any hassle. It preserves original data while combining PST files. Also supports the merger of both ANSI and UNICODE files in Outlook PST. You can also use the trial version of this software. Visit here for more info: https://www.softakensoftware.com/merge-outlook-pst.html