How to Fix Outlook Start-up Errors in Windows

Windows • Ryder Cragie • 5th September 2022

Notices and Disclaimers


If Outlook doesn’t open and you see an error, the data file may have been corrupted. This article will explain how to fix it.

What are Outlook Data Files?

Outlook data files store the contents of your emails, headers, metadata, and the mailbox structure. They have file extensions of ".pst", ".nst" and ".ost". Sometimes these files become damaged or corrupted resulting in the Outlook application either running slowly or not running at all. The data files may need to be repaired or recreated.

Run System Scans and Repairs

Repair Original Data Files

If running system scans and repairs didn't help, you can try repairing the Outlook data files.

If any of the above directories do not exist, try without " (x86)" in the path.

Delete Original Data Files

If repairing the Outlook data files didn't help, you can try deleting and recreating them.

Don't worry if one of the folders doesn't exist.

Create New Data Files


You should now be able to launch Outlook without any problems. For further help, please see the official Microsoft documentation.