How to Repair and Recover Corrupt Outlook Data Files?

Microsoft Outlook is a widely used email client, cherished for its extensive features and user-friendly interface. However, like any software, Outlook is not immune to issues, and one common problem users encounter is corrupt data files. Corrupt Outlook data files, whether PST (Personal Storage Table) or OST (Offline Storage Table), can lead to data loss and hinder productivity. In this blog post, we will discuss how to repair and recover corrupt Outlook data files, addressing both PST and OST files separately.

Part 1: Repairing and Recovering Corrupt PST Files

PST files store your mailbox data, including emails, contacts, calendar events, and more. When a PST file becomes corrupt, you may experience issues such as Outlook not opening, PST file error messages, or missing data. Here’s how to repair and recover a corrupt PST file:

1. Use the Inbox Repair Tool (ScanPST.exe):

Microsoft provides a built-in tool called ScanPST.exe to repair corrupt PST files. It’s typically located in the following directory:

  • For Outlook 2019, 2016, 2013, and 2010: C:\Program Files (x86)\Microsoft Office\root\OfficeXX
  • Close Outlook and run ScanPST.exe.
  • Select the corrupt PST file and click “Start.”
  • ScanPST will identify and repair errors. Make sure to back up your PST file before proceeding.

2. Create a New PST File:

Sometimes, the corruption is too severe to repair. In such cases, you can create a new PST file and import the data from the corrupt file:

  • Open Outlook and go to “File” > “Account Settings” > “Data Files” tab.
  • Add a new data file (PST).
  • Set it as the default data file and close Outlook.
  • Reopen Outlook, go to the old PST file, and manually copy or move folders to the new PST file.

3. Use a Third-party PST Repair Tool:

If ScanPST fails to repair the corrupt PST file, consider using third-party tools like Stellar Repair for Outlook or Kernel for Outlook PST Repair. These tools are specifically designed to handle complex PST file corruption.

Part 2: Repairing and Recovering Corrupt OST Files

OST files are copies of your mailbox data stored on the Exchange server. When an OST file becomes corrupt, it can prevent you from accessing your mailbox an throw up different OST file error messages. Here’s how to repair and recover a corrupt OST file:

1. Use the Inbox Repair Tool (ScanOST.exe):

Similar to ScanPST for PST files, Outlook used to have a built-in tool called ScanOST.exe to repair OST files. However, starting with Outlook 2013, this tool was removed. In newer versions of Outlook, it is recommended to recreate the OST file by deleting the existing one and letting Outlook rebuild it from the server.

2. Convert OST to PST:

When an OST file is severely corrupt and cannot be repaired, you can convert it to a PST file:

  • Exit Outlook and make sure it’s not running in the background.
  • Download and install Magus OST to PST converter tool.
  • Open the tool, select the corrupt OST file, and choose the location to save the PST file.
  • Follow the software’s instructions to complete the conversion.

How to Prevent Outlook data file corruption?

Preventing Outlook data file corruption is crucial for maintaining a smooth email management experience and avoiding data loss. Here are some preventive measures to help you avoid Outlook data file corruption:

Regular Backups:

Schedule regular backups of your Outlook data files (PST and OST). You can use the built-in Export feature to create backup copies of your mailbox data. Storing these backups in a safe location, such as an external hard drive or cloud storage, ensures that you can recover your data in case of corruption.

Maintain Mailbox Size:

Keep your mailbox size in check by regularly archiving or deleting old emails, attachments, and calendar items. A large mailbox can increase the risk of corruption.

Avoid Oversized PST Files:

PST files have size limitations, and exceeding these limits can lead to corruption. For Outlook 2019 and earlier, the recommended maximum size is 50 GB. For Outlook 2016 and 2013, it’s 50 GB, but there are ways to increase it. However, it’s best to keep PST files reasonably sized.

Use a Reliable Storage Device:

Store your PST and OST files on a reliable and stable storage device. Avoid using network drives, removable drives, or cloud-synced folders for storing these files, as network interruptions or syncing issues can lead to corruption.

Close Outlook Properly:

Always close Outlook properly rather than forcefully shutting down your computer or killing the Outlook process. This ensures that Outlook has a chance to complete any ongoing tasks and properly save data.

Disable Add-ins:

Some Outlook add-ins can be unstable and cause data file corruption. Disable unnecessary add-ins and only use those that are from reputable sources and regularly updated.

Keep Outlook and Windows Updated:

Regularly update both Outlook and your Windows operating system to ensure you have the latest security patches and bug fixes. Outdated software can be more vulnerable to corruption.

Use Cached Exchange Mode Wisely:

If you use Cached Exchange Mode, be mindful of the size of your offline OST file. Large OST files can be more prone to corruption. Adjust the caching settings to only download recent data or use Online Mode for a smaller OST file.

Run Antivirus and Anti-malware Scans:

Keep your computer protected with up-to-date antivirus and anti-malware software. Viruses and malware can corrupt your Outlook data files.

Avoid Forceful Terminations:

Never forcefully terminate Outlook, especially when it’s in the middle of a task like sending or receiving emails. Ensure that Outlook has completed its tasks before closing it.

Use a Robust Internet Connection:

A stable and high-speed internet connection is essential when using Outlook, especially if you are working with Exchange servers. Frequent disconnects can lead to corruption in OST files.

Monitor for Hardware Issues:

Keep an eye on the health of your computer’s hard drive or storage device. Hardware issues can sometimes corrupt data files.

By implementing these preventive measures, you can reduce the risk of Outlook data file corruption and ensure the integrity of your email data. Regular maintenance and responsible email management are key to a trouble-free Outlook experience.


Dealing with corrupt Outlook data files, whether PST or OST, can be a frustrating experience. However, by following the steps mentioned above, you can often repair and recover your valuable email data. Remember to regularly back up your Outlook data files to minimize the risk of data loss and consider using reliable third-party tools when needed. With the right approach, you can ensure that your Outlook experience remains smooth and efficient.

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