There can be number of reasons of looking a medium by which you can open or read or view orphan PST files. So, free PST Viewer tool is the solution for your search. Try the software if do not want to invest a single penny. It supports files from any version of Outlook and will work on both Windows and Mac OS. It previews like Outlook with different sections. For attachments, for Preview of mails and attachments can be viewed at right side. Folder hierarchy is also remains same as it was actually in the Outlook. Allows to open pst files from external and USB drives. Main advantage of the PST Viewer is that it will allow to view files which are password protected and for that you don't need to know password.