Cannot start Microsoft Outlook

Look for the file SCANPST.EXE and run it, it is part of the Office installation. Browse to the problem .pst file you wan to repair.

https://support.office.com/en-us/article/Repair-Outlook-Data-Files-pst-and-ost-25663bc3-11ec-4412-86c4-60458afc5253

Repair an Outlook data file (.pst) file

1. Exit Outlook and browse to one of the following file locations:

   • 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\Office10

2. Open SCANPST.EXE.

3. Select Browse to select the Outlook Data File (.pst) you want to scan. If you need help locating your Outlook Data File, see Locating the Outlook Data Files.

   Note: By default, a new log file is created during the scan. You can choose Options and opt not to have a log created, or you can have the results appended to an existing log file.

4. Choose Start to begin the scan.

5. If the scan finds errors, choose Repair to start the process to fix them. Note: The scan creates a backup file during the repair process. To change the default name or location of this backup file, in the Enter name of backup file box, enter a new name, or choose Browse to select the file you want to use.

6. 1. When the repair is complete, start Outlook with the profile associated with the Outlook Data File you just repaired.

   What happens after you repair an Outlook Data File?

   In the Folder Pane, you might see a folder named Recovered Personal Folders that contains your default Outlook folders or a Lost and Found folder. Although the repair process might recreate some of the folders, they may be empty. The Lost and Found folder contains any folders and items recovered by the repair tool that Outlook can't place in their original structure.

   Create new data file

   You can create a new Outlook Data File and drag the items in the Lost and Found folder into the new data file. After you've moved all the items, you can remove the Recovered Personal Folders (.pst) file, including the Lost and Found folder.

   Recover items from the backup (.bak) file

   If you can open the original Outlook Data File, you might be able to recover additional items. The Inbox Repair tool creates a backup file with the same name as the original, but with a .bak extension, and saves it in the same folder. There may be items in the backup file that you might be able to recover that the Inbox Repair tool couldn't.

   1. Browse to the folder where the .pst file is stored and you'll find the .bak file (for example, kerimills01@outlook.com.bak) created by the Inbox Repair tool.

   2. Make a copy of the .bak file and rename it with a bak.pst extension. For example, kerimills01@outlook.com.bak.pst.

   3. Import the bak.pst file into Outlook, and use the Import and Export Wizard to import any additional recovered items into the newly created .pst file.