You can easily convert OST file to PST format without Microsoft Outlook installed in your computer. This task can be easily done by using EmailsGuru OST to PST Converter. It allow users to convert OST file to PST format, saving emails, contacts, calendars, notes and all other Outlook items. It is designed with simple and intuitive interface so that even non-technical users can effortlessly convert OST file to PST file format with or without Outlook. It is Windows based utility thus users can smoothly run it on all versions of Windows OS and use a free trial version to convert 25 items from an OST file to PST format.

Read more- https://www.emailsguru.com/ost/pst/