Step 1: Exit Outlook and do one of the following:

Browse to C:\Program Files.
(or)
Browse to C:\Program Files (x86).

Step 2: In the Search box, type SCANPST.EXE.

Note: If the search doesn't find SCANPST.EXE in one folder, try searching in the other folder mentioned in step 1. Navigate to the folder location based on your version of Outlook.

Outlook 2016: C:\Program Files (x86)\Microsoft Office\root\Office16

Outlook 2013: C:\Program Files (x86)\Microsoft Office\Office15

Outlook 2010: C:\Program Files (x86)\Microsoft Office\Office14

Outlook 2007: C:\Program Files (x86)\Microsoft Office\Office12

Step 3: Open SCANPST.EXE.
Step 4: In the Enter the name of the file you want to scan box field, enter the name of the .pst file you want the tool to check, or choose Browse to select the file.
Step 5: If the scan finds errors, choose Repair to start the process to fix them.
Step 6: When the repair is complete, start Outlook with the profile associated with the Outlook Data File you just repaired.