OST to PST Conversion Freeware - Version 3.4 OST to PST Conversion Freeware application management tool converts OST emails, contacts, calendar, schedules, tasks, attachments, notes, journal and other significant items. Maintain the formatting of the RTF and HTML messages.OST File Conversion Software works for Microsoft Outlook 2010, 2007, 2003 and 2000. OST File Conversion software convert the OST data (inbox, outbox, calendar, contacts, tasks etc.) to PST. You can easily download demo version of this software if you fulfilled this software recovery process then purchase full version of our software just at $99.