This command deletes the custom folder views, restoring default configurations. It’s harmless and resolves 30% of stuck startup issues according to Microsoft community reports. Microsoft provides a built-in tool called SCANPST.EXE to scan and repair minor OST corruption. If a Microsoft 365 application such as Word or Excel isn't working correctly, sometimes restarting it will fix the Troubleshoot Office 365 Sync and Login Issues problem. It is located in the folder of your original Personal Folders (.pst) file.

Step 3 - Recover repaired items to a new .pst file

• If you can't start the Inbox Repair tool automatically or manually, you may try to repair your Office application.
• Yes — Outlook will re-sync mailbox data from the server once you relaunch the app, as long as you use an Exchange or Office 365 account.
• The platform validates SMTP, IMAP, and POP3 settings against verified databases to identify version mismatches or broken profiles introduced after system updates.
• In this 2025 guide, we’ll show you how to repair the Outlook OST file and restore seamless email performance without losing important data.
• If Outlook is unresponsive, not opening, or is crashing without any morning you can repair using the tried and tested methods provided here.
• If your Outlook suddenly stopped opening after a Windows update, don’t panic.
• While carrying out the above methods it is advisable to close Outlook beforehand.

Therefore, structures such as BTrees and reference counts, are checked and repaired as necessary. These low-level objects have no knowledge of the upper-level structures, such as messages, calendar items, and so on, that are built upon them. After you run the Inbox Repair tool, you can start Outlook and recover repaired items. Optionally, you can try to recover additional repaired items from the backup personal folder. Solutions like opening Outlook in safe mode, recreate Outlook profile step by step fixing Outlook profile, and Repairing Outlook using Microsoft Office using the in-built tool.

Can I delete my OST file without losing data?

If all the above methods were unsuccessful, you could take a closer look at the Outlook data file instead. If that does not work you can try using SFWare PST repair software. The last option in this list is to repair the Outlook data file.

Easily Repair Outlook 365 and Outlook 2021, 2019, 2016, 2013, 2010, 2007, & Other Versions

Fortunately, most of these errors stem from configuration conflicts, corrupted data files, or outdated components that can be fixed with a few targeted steps. If your Outlook suddenly stopped opening after a Windows update, don’t panic. Most startup failures arise from minor configuration mismatches or outdated components. Following the above steps—from safe mode diagnostics to repairing data files—will restore functionality in most cases. Repairing Outlook’s .OST and .PST files often restores full mailbox synchronization and prevents email loss.

Repair Outlook OST File Not Working in Office 365 – Complete Fix (

You’ll see files ending with ".ost" — these store your cached mailbox data. The steps to access the repair tool vary depending on your operating system. To start, create a new Personal Folders (.pst) file entry in your profile. Then, you can move the recovered items to your new Personal clear Outlook credentials manager Folders (.pst) file.