How to Repair a Damaged Outlook PST File Without Losing Mail

This guide walks you through repairing a corrupted Outlook Personal Storage Table (PST) file while keeping your emails, contacts, and calendar items intact. The built-in repair tool is the safest first step; third-party tools are a backup if that fails. You will need access to your Outlook account and the ability to close programs.

What You’ll Need

Your Windows PC with Outlook installed
The exact location of your PST file (usually in Documents\Outlook Files)
Administrator rights on the computer (for some repair steps)
Optional: a USB drive or cloud storage for a backup copy

Step-by-Step

Close Outlook completely. Click the X on the window, then check the system tray (bottom-right corner) for the Outlook icon. Right-click it and select “Exit” to ensure no background processes are running.
Locate your PST file. Open File Explorer and navigate to %userprofile%\Documents\Outlook Files. Look for a file ending in .pst or .ost. If you don’t see it there, use Windows Search and type *.pst. Note the full path.
Create a backup copy. Right-click the PST file and select “Copy”. Right-click an empty area in the same folder and select “Paste”. Rename the copy to something like backup.pst. This ensures you have a fallback if the repair goes wrong.
Run the Inbox Repair Tool (Scanpst.exe). This tool ships with Outlook. The location varies by version:
- Outlook 2019/2016: C:\Program Files\Microsoft Office\root\Office16\
- Outlook 2013: C:\Program Files\Microsoft Office\Office15\
- Outlook 2010: C:\Program Files\Microsoft Office\Office14\
- Outlook 365: C:\Program Files\Microsoft Office\root\Office16\
If you have 32-bit Office on 64-bit Windows, the path starts with C:\Program Files (x86)\ instead.
Open Scanpst.exe. Double-click it. In the window that appears, click “Browse” and select your PST file (the original, not the backup). Click “Start”.
Let the scan complete. The tool will check for errors. This can take several minutes for large files. Do not interrupt it. When it finishes, it shows a log. Click “Repair” if errors were found, or “Close” if none were.
Check the result. Open Outlook and see if your mail appears. If the repair fixed the issue, you’re done. If Outlook still shows errors or the repair tool fails, proceed to the next step.
Use the backup (if repair failed). If Scanpst could not fix it, delete the damaged PST and rename your backup back to the original name. This restores your data to its pre-corruption state. Then try opening Outlook again.
Create a new PST and import (last resort). In Outlook, go to File > Account Settings > Account Settings. Click the “Data Files” tab, then “Add”. Name it recovered.pst. Then go to File > Open & Export > Import/Export > Import from another program or file > Outlook Data File (.pst). Select your damaged file and import into the new one. This often salvages mail even when the repair tool cannot.

Common Mistakes

Skipping the backup. Running Scanpst on a file without a copy is risky. If the repair corrupts it further, you lose everything.
Running the tool on an OST file. Scanpst works on PST files. For OST (offline cache), delete the OST and let Outlook rebuild it from the server. This is normal and does not lose server-side mail.
Using the wrong version of Scanpst. Using a 32-bit tool on a 64-bit install (or vice versa) causes a crash or “cannot find” error. Check your Office version in File > Account.
Interrupting the scan. Clicking “Cancel” or closing the window mid-scan can make the file worse. Patience is critical.

Tips

Always close Outlook before running Scanpst. The tool cannot access a file in use.
If you use Outlook 365, the tool is the same as 2016. Do not download “new” versions from random websites; the official one is already on your PC.
For very large PST files (over 20 GB), the scan may take over an hour. Let it run overnight if needed.
Consider splitting your PST into smaller archives after repair to reduce future corruption risk.

Troubleshooting

Scanpst.exe won’t open. Right-click it and select “Run as administrator”. If it still fails, your Office installation may be damaged. Repair Office via Control Panel > Programs > Microsoft Office > Change > Quick Repair.

The tool says “Cannot find file”. The path you browsed to may be an OST or a different format. Verify the file extension. Also check that you have permission to read the folder; if it’s on a network drive, copy it locally first.

Repair completes but Outlook still shows errors. Run Scanpst a second time. Some corruption is layered. If it persists, use the import method in Step 9 to pull items into a fresh PST.

Outlook crashes when opening the repaired file. The file may be too large or fragmented. Try compacting the PST: File > Account Settings > Data Files > Settings > Compact Now. If that fails, export to a new PST from the damaged one.

No backup was made and repair failed. Stop using the file immediately. Try a third-party recovery tool (like Stellar or Kernel) that can read the raw data. Free trials often let you preview recoverable items before purchase.

Mail appears but attachments are missing. This is a sign of partial corruption. Run Scanpst again, then check the “Deleted Items” folder—sometimes items get moved there during repair.

Frequently Asked Questions

Q: Will Scanpst delete my emails?
A: No. It attempts to repair the structure and preserves the content. In rare cases, items that are too damaged may be moved to a “Lost and Found” folder, but they are not deleted.

Q: How long does the repair take?
A: For a 2 GB PST, expect 10-20 minutes. For 10 GB+, it can take over an hour. Speed depends on CPU and disk speed.

Q: Can I repair a PST on another computer?
A: Yes. Copy the PST to a PC with Outlook installed and run Scanpst there. This is often safer if your main machine has issues.

Q: Is there a free alternative to Scanpst?
A: No reliable one. The built-in tool is free and usually sufficient. Third-party tools are paid, though some offer free trials for preview.

Q: What causes PST corruption?
A: Abrupt shutdowns, disk errors, exceeding the 2 GB limit in older Outlook versions, and antivirus software scanning the file while Outlook writes to it are common causes.

Q: Should I convert my PST to a new format?
A: If you’re on Outlook 2013 or later, the file is already in Unicode format. Older ANSI PSTs (from Outlook 2002 and earlier) are more fragile; consider migrating to a modern format.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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