If you are a regular user who depends heavily on the inbox application to perform daily operations, then Outlook not working or opening would be a big punch in the gut. Yes ✅ You can connect with our experts on WhatsApp for quick remote support and step-by-step troubleshooting guidance. fix MFA prompts not working 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 Inbox Repair tool is automatically installed with all English-language Microsoft Outlook installation options depending on your operating system.

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.
• For persistent issues, use FixTechGuide’s automated tools to perform deep diagnostics and security checks.
• In this 2025 guide, we’ll show you how to repair the Outlook OST file and restore seamless email performance without losing important data.
• When Outlook is not working, or Outlook keeps crashing pondering upon the cause won’t be of use unless it is a regular issue.
• 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, fix Outlook after Windows update issues 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

If it does not work, then unfortunately, you will be unable to recover any additional information. If you could open the file, the following procedure may help you recover additional items from your damaged Personal Folders (.pst) file. If you can't start the Inbox Repair tool automatically or manually, you may try to repair your Office application.

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 Office 365 Sync Errors Fix Folders (.pst) file.