To
convert your ost file to pst file format without any difficulty you can rely on
Dux convert ost to pst free software which can recover your ost file and can
convert ost to pst as well as different file formats like EML,MSG,TXT,RTF and
office 365. Advantage of using this software is that it support outlook version
97 to 2019.
https://www.duxdatarecovery.com/ost2pst/best-ost-to-pst-converter-software/