OST (Offline Storage Table) files serve as a typical means for Microsoft Outlook to retain offline replicas of mailbox data. Nonetheless, circumstances might emerge demanding the conversion of OST files to PST (Personal Storage Table) format sans Outlook installation. Such instances could stem from diverse factors such as Outlook being inaccessible, OST file corruption, or the necessity to access mailbox data across alternate platforms. Thankfully, there exists a solution to seamlessly convert OST to PST without Outlook installation. 

There are various ways to convert OST to PST format.

1. There are many third-party OST to PST conversion tools available that can efficiently convert OST files to PST format without requiring Outlook. These software packages typically provide a user-friendly interface and offer various features to ensure a smooth conversion process. One such tool is the Advik OST to PST Converter for Windows.

2. If you have access to a system with Outlook installed, you can use the built-in Import/Export feature to convert OST to PST manually. Here's how:

a. Open Outlook and go to File > Open & Export > Import/Export.

b. Select "Export to a file" and click Next.

c. Choose "Outlook Data File (.pst)" as the export option and click Next.

d. Select the mailbox folder you want to export (typically, the entire mailbox), and choose a location to save the PST file.

e. Click Finish to start the export process. Once completed, you'll have a PST file containing the converted data.
 

If any other method is there to convert ost to pst, then please share them.