If you are searching for Free Unlimited OST to PST Converter tool then you can try the eSoftTools OST to PST converter. This tool allows converting OST files to PST with accuracy. It supports all window versions like XP, 7, 8, 10, and onward and MS Outlook 2003, 2007, 2010, 2013, etc. It’s 100% tested from anti-virus and online scanners. it has many features for conversion OST to PST like name convincing, advanced filter with date and range, and many more. You can also try a free demo version.