There are many tools is available in the market for better OST Conversion but I recommend you the well-known SoftMails OST to PST Converter software. You can use this tool without any technical knowledge and it can easily recover the OST file emails, documents, deleted files, attachments, appointments, contact, calendar, tasks, notes, chats, msg, etc. That can support all versions of MS Outlook or Windows OS and is also capable to run on all versions of Windows like 8, 9, 10, XP, and many more formats. You can get the demo version and also use the demo version from the official website of SoftMails.
Read More:- Convert OST file to PST
Convert OST to PST Manually
Open Outlook and go to the File menu.
Select the Import/Export option.
Choose Export to a file.
Select Outlook Data File (.pst)
Choose whether to export a specific folder or the whole account.
Check the Include subfolders box.
Next, select a destination for the Export, and then click Finish.