If you want to recover corrupt OST files into PST format. Try this eSoftTools OST to PST Recovery Tool. This tool can recover all items such as attachments, contacts, calendar, contact, emails, tasks, notes, etc. it supports all window versions like XP, 7, 8, 10, and onward. Also, the tool can convert all OST files into PST, EML, MSG, MBOX, office 365, Gmail, etc. OST to PST Converter tool provides a free demo version.