Open or read the OST file without Outlook with Data Recovery Freeware OST viewer Freeware. this tool helps to recover all your database like Contacts, Calendars, emails, attachments, etc. It is compatible with 32bit and 64bit operating systems. This amazing tool helps to recover OST files into multiple file formats like HTML, PST, OST, and many others file formats. Moreover, its user-friendly user interface helps to perform this process very smoothly.