PST repair tool also called as Scanpst.exe is designed by Microsoft to repair your Outlook data files stored in a personal storage table (.PST) file. This file contains all the user data comprising emails, contacts, events and calendar details etc.
The format and organization of this data is defined by a table. When there is any kind of mismatch in the format your data tends to get corrupted. This same table is referred by PST repair tool (Inbox repair tool) to reconstruct the file structure.
However, severe corruptions require complex reconstructions that might not be handled by Scanpst.exe. The following information is presented to help you understand:
Scanpst works on the source PST file to repair & recover data. It checks each row of a table and verifies if messages or subfolders exist in the file by referring to table.
It carefully checks the directory of PST file looking for headers and other low-level objects like the B-tree structures that hold the reference counts and data. If any errors are found the tool repairs and recovers the damaged information.
Scanpst is automatically called when any errors are detected while trying to open you PST file. However, if you wish to run Scanpst on a desired PST file at your will, you can find Scanpst in the app data. The location of Scanpst is unique to every version of Outlook.