How to Open an Orphaned OST File in Outlook 2025

[smithjens]

An orphaned OST file cannot be opened directly in Outlook 2025 because it is linked to the original Outlook profile or Exchange account. When that profile is missing, Outlook won’t read the OST file.

The simplest way to open an orphaned OST file is to convert it into PST format first. A reliable tool like Advik OST to PST Converter helps you extract all emails, attachments, contacts, and calendars from the orphaned OST file and save them into a PST file that Outlook 2025 can open easily.

Steps:

1. Install and run Advik OST to PST Converter.
2. Add your orphaned OST file.
3. Choose PST as the output format.
4. Click Convert and wait for the process to finish.
5. Import the converted PST into Outlook 2025.

This method works for corrupted, old, or oversized OST files and ensures all your data remains intact.