Repair Corrupted PST File: 8 Ways That Work

Updated 7 November 2026 · Standard formula, shown below

If Outlook won’t open your data file or shows errors, the PST is likely corrupted. You can repair it using built-in tools like Scanpst.exe, or third-party recovery software, depending on the severity. This guide covers the most effective methods, from Microsoft’s free utility to manual workarounds.

What Causes PST Corruption?

PST (Personal Storage Table) files store your emails, contacts, calendar, and tasks. Corruption usually happens when the file is abruptly interrupted—during a power outage, a system crash, or when Outlook closes improperly. Other common triggers include:

Storing the PST on a network drive or cloud-synced folder (OneDrive, Dropbox) where file locking is unreliable.
Exceeding the file size limit of older PST formats (usually 20 GB for Outlook 2003 and earlier; newer versions support up to 50 GB with Unicode).
Malware or antivirus software that scans and locks the PST while Outlook is writing to it.
Hard disk errors or bad sectors on the drive where the PST resides.

Understanding the cause helps you choose the right repair method—and prevents future corruption.

Method 1: Run Inbox Repair Tool (Scanpst.exe)

Microsoft ships a free repair utility with every Outlook version. It’s called Scanpst.exe (Inbox Repair Tool). It scans the PST for structural errors and attempts to rebuild the file. Here’s how to use it:

Close Outlook completely.
Locate Scanpst.exe. For 64-bit Outlook on Windows 10/11, it’s usually in C:\Program Files\Microsoft Office\root\Office16\. For 32-bit, it’s in C:\Program Files (x86)\Microsoft Office\root\Office16\. The folder number (16, 15, 14) depends on your Office version.
Run the tool, then click Browse to select your PST file. You can find its path in Outlook under File > Account Settings > Data Files.
Click Start. The tool will scan and report errors. Click Repair to fix them.
After repair, open Outlook and check if your data is intact. If not, run the tool a second time—sometimes a second pass catches more errors.

Important: Scanpst.exe repairs the structure of the file, not the logical content. If emails are missing or garbled after repair, the data itself may be unrecoverable with this tool.

Method 2: Create a New PST and Import

If Scanpst.exe fails or you can’t open the file at all, you can try creating a brand-new PST and importing the old one. This works when the corruption is isolated to certain folders or records.

In Outlook, go to File > Account Settings Data Files.
Click Add, choose Outlook Data File (.pst), and give it a name (e.g., “NewPST”).
Set it as the default delivery location (optional).
Go to File > Open & Export > Import/Export.
Choose Import from another program or file, then select Outlook Data File (.pst).
Browse to the corrupted PST. Outlook will attempt to read it. If it succeeds, you can import items into the new file.

This method is less effective than Scanpst.exe for severe corruption because Outlook’s import engine also reads the file structure—if that’s broken, it won’t work.

Method 3: Use the Free Microsoft PST Recovery Tool (for Older Versions)

For Outlook 2007 and earlier, Microsoft offered a separate downloadable tool called PST Recovery Tool (not to be confused with Scanpst.exe). It was a command-line utility that could extract items from a corrupt PST and save them to a new file. However, Microsoft discontinued it, and it’s no longer available for modern Outlook. If you have an old PST from those versions, you might find the tool on third-party archives, but use caution—it’s unsupported and may not work on newer systems.

Method 4: Recover Items from the Recoverable Items Folder

Sometimes corruption manifests as “missing” emails, not a completely unopenable file. If Outlook opens but items are gone, check the Recoverable Items folder:

Go to the Deleted Items folder.
Click the Recover items recently removed from this folder link at the top.
Select the items and click Restore selected items.

This only works if the items were deleted recently and the mailbox is still within the retention period. It doesn’t help with structural corruption, but it’s a quick first step if you’re missing data after a crash.

Method 5: Use a Third-Party PST Repair Tool

When Microsoft’s tools fail, commercial software like Stellar Repair for Outlook, Kernel for Outlook PST Repair, or DataNumen Outlook Repair can often recover more. These tools use deeper scanning algorithms to rebuild the PST file and extract individual items (emails, contacts, calendar entries) even when the file structure is severely damaged.

How to choose one:

Free trial: Most offer a free trial that lets you scan and preview recovered items. Use this to see if your data is actually recoverable before paying.
Compatibility: Ensure the tool supports your Outlook version (e.g., Outlook 2016, 2019, 2021, Microsoft 365) and your PST format (Unicode vs. ANSI).
Output options: Good tools let you export to a new PST, or directly to Outlook, or as individual .msg files.
No installation on the corrupted drive: If possible, install the tool on a different drive than the PST to avoid further write operations on the failing disk.

Cost: Prices typically range from $50 to $150 for a single-user license. Some tools offer a free version that repairs files up to a certain size (e.g., 50 MB), which is fine for small PSTs but not for large ones.

Method 6: Move the PST to a Local Drive

If your PST is on a network share, USB drive, or cloud-synced folder, move it to a local internal drive first. Network and cloud storage often cause file locking issues that lead to corruption. After moving, try opening it in Outlook. Sometimes the corruption is just a temporary file conflict, and moving the file resolves it.

Close Outlook.
Copy the PST file to C:\Users\YourName\Documents\Outlook Files\ (or any local folder).
In Outlook, go to File > Account Settings Data Files > Add and select the moved file.
Remove the old (broken) file from the list.

Method 7: Use a Previous Version (Shadow Copy)

Windows creates shadow copies of files if System Protection is enabled. You can restore an earlier version of the PST before it got corrupted.

Right-click the PST file in File Explorer.
Select Properties > Previous Versions tab.
Choose a version from before the corruption occurred and click Restore.

This only works if you have restore points or File History enabled. It’s a long shot, but it can save you from using paid tools.

Method 8: Recreate the PST from an OST (Offline Storage Table)

If you use an IMAP or Exchange account, Outlook keeps a cache in an OST file. If your PST is corrupted but the OST is intact, you can recreate the PST from the OST.

Close Outlook.
Rename the corrupt PST file (e.g., to .old).
Restart Outlook. It will create a new PST.
If your account is IMAP, Outlook will re-download all emails from the server. For Exchange, it will re-sync from the mailbox.

This doesn’t recover data that only existed in the PST (like local folders), but it gets you back to a working state.

Frequently Asked Questions

Can I repair a PST file without Scanpst.exe?

Yes. You can try the import method, move the file to a local drive, or use a third-party tool. Scanpst.exe is the first line of defense, but it’s not the only option.

How long does Scanpst.exe take?

It depends on the file size. A 2 GB PST might take 10–20 minutes; a 50 GB PST can take several hours. The tool shows progress, so you can monitor it.

Will repairing a PST delete my emails?

No. The repair process creates a backup copy of the original file (usually with a .bak extension) before making changes. If the repair fails, you can restore the backup. However, if the file is severely damaged, some items may be unrecoverable.

What’s the difference between PST and OST?

PST is a personal folder file used for POP3, IMAP, or archived data. OST is an offline cache for Exchange or Microsoft 365 accounts. You can’t directly open an OST in Outlook without the associated account, but you can convert it to a PST using export or third-party tools.

Can I prevent PST corruption?

Yes. Always close Outlook properly, keep the PST on a local drive, avoid exceeding the size limit, and regularly back up the file. Using a UPS (uninterruptible power supply) also helps prevent corruption from power outages.

Is it worth paying for a third-party tool?

If your PST contains irreplaceable business data or years of personal emails, yes. The free tools only repair structure; paid tools can often recover individual items that Scanpst.exe misses. Try the free trial first to see if your data is recoverable.

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