How to convert OST to PST file
The OST to PST file converter can be installed on computers running Windows with Microsoft Outlook installed. You do not need to be connected to the Internet.
The tool lets you convert Microsoft Exchange Server and Microsoft Outlook databases (*.OST files) into Microsoft Outlook Personal Store Folders (*.PST files) on personal computers or servers that have Microsoft Outlook installed. The osttopst converter works without an Internet connection.
- In order to convert OST files that are larger than 4GB, you must have the 64-bit version of Microsoft Outlook installed on your computer with Microsoft Outlook OST PST Converter.
- You must have Microsoft Outlook installed on your computer in order to export data to a PST file. Outlook in Office 365, Outlook for iOS, and Outlook for MacOS do not allow you to export data to a PST file.
- You cannot export groups of contacts from OST to PST files.
A step-by step description of converting an OST file of any version and size to a Microsoft Outlook PST file using a personal computer: