Make use of OST to PST tool for Outlook open OST file without Exchange in PST format on all Windows Operating Systems i.e. Win 10, 8.1, 8, 7, XP, Vista, etc. The OST to PST Conversion Tool is an excellent utility which supports batch conversion from OST folder to PST format in one time process. First, you must try its free download version which allows you to save first 25 items from OST file to PST file format without cost. For Outlook open OST file without Exchange in PST format in bulk mode, then you need to go with the license key of the OST to PST Tool.