For the smooth and safe conversion, I suggest you ATS OST to PST Converter tool that is the first choice of every Outlook user who wants to convert the data from OST file to Outlook PST file format. After the conversion, you can preserve your data into several file formats like PST, EML, HTML, EMLX, MSG, MBOX, vCal, vCard for future use. If you can show the preview of the recovered mailbox before the conversion. Using this utility you can your lost and permanently deleted data. It supports the version of OS Windows like 95, NT, 98, ME, XP, Vista, 7, 8, and 8.1,10 (32bit & 64bit).