In my idea, you can try a manual way to convert offline OST to Outlook PST format. But, as you are finding for the OST to PST File Migration Software, then I would recommend you try OST to PST Migration because it has a free demo version which helps users to know its working procedure and features and it is well-matched with all versions of Windows.

OST to PST Converter is an automated and reliable utility that is used to convert all your Exchange OST files into PST file format with all their mail attachments. This tool has the ability to convert OST mailboxes into several file-formats including PST, EML, PDF, MBOX, TXT, HTML. It comes with amazing features such as user-friendly interface and graphical user interface. It offers a free trial that helps in evaluating the functionality of the software. A free 24*7 technical experts are also available to help the users. Just before the conversion, the software displays a preview of OST items. I would recommend you use this reliable utility to convert OST files into PST files.

The manual technique is the only free way to convert as many OST files as you like to PST format, but it is not a safe way to do it. I'd like to suggest a solution that makes it possible to convert any size OST file to PST file format without causing any data loss. TheOST to PST Converter is enough to convert OST files of any size to PST file format. Any Windows version, new or old, can have this utility installed by users. Prior to the conversion process starting, users can preview their chosen OST database. Additionally, this tool was compatible with every version of Microsoft Outlook, including: 2002, 2003, 2007, 2010, 2013, 2016, and 2019. This utility can convert OST files to PST file format for both technical and non-technical users. To learn more about this tool's features and properties, use the free demo version.
Read More:- https://www.osttopstapp.com/