Microsoft Outlook is a powerful all-in-one personal information manager that tracks emails, calendars and tasks and includes a host of other features.
When the files matter or the fault is physical, the safest route is a lab: see Bot’s professional data recovery, which starts with a free diagnosis.
Unfortunately, the way the program is built puts a lot of your digital information in a single basket. For POP accounts and local archives, Outlook’s PST (Personal Storage Table) file is often the only copy of your emails, contacts and calendar.
So if it becomes corrupted or damaged, you risk losing everything stored in it.
If you can’t open your Personal Folders file (.pst) or suspect that it is corrupted, the tips in this article will help you recover it without losing your data. We’ll also look at the most common causes of PST corruption.
What is a PST file?
The PST format is used to store local copies of Outlook data, such as emails, calendar events, contacts and tasks.
PST files are also widely used to export Outlook data and import it on other computers.
In addition, using PST files for archiving helps administrators save a significant amount of storage space on mail servers.
Because PST files are so useful, it’s well worth knowing how to recover them.
Where are PST files stored?
In Windows 10 and later, PST files created by older versions of Outlook (2007 and earlier) are usually found in:
C:\Users\<username>\AppData\Local\Microsoft\Outlook or C:\Users\<username>\AppData\Roaming\Microsoft\Outlook.
Even in newer versions of Outlook, the OST files used by Exchange, Microsoft 365 and IMAP accounts are still stored in the first of these folders.
Note that these folders are usually hidden. To see them, turn on hidden items in File Explorer (View > Show > Hidden items).
From Outlook 2013 onwards, new PST files are saved by default in C:\Users\<username>\Documents\Outlook Files.
Outlook can also show you the exact location of your PST files.
To do this, follow these steps:
- Open Outlook
- Click on “File”
- Click the “Account Settings” drop-down menu and select “Account Settings”
- In the window that opens, click the “Data Files” tab
- In the list of data files, select the PST or OST file you need and click “Open File Location” to see it in File Explorer.
What are the causes of PST file corruption?
The PST file is a complex binary format that was not designed to be fault-tolerant. That’s why so many different situations can corrupt it.
Bad sectors on the hard disk
A bad sector is a small area of storage on a disk that has become defective, which means it no longer responds reliably to read or write requests.
Bad sectors (or bad blocks) can occur on both traditional magnetic hard drives (HDDs) and modern solid-state drives (SSDs).
There are two types of bad sectors: those caused by physical damage, which cannot be repaired, and logical ones caused by software errors, which can be corrected.
Whatever the type, bad sectors can corrupt any file, including .pst files. If your disk is developing bad sectors, copy your data off it as soon as possible, or stop using it if it shows signs of physical failure.
Network problems
Some organizations keep PST files on a central file server, with users opening them over the network. Microsoft does not support this configuration.
In this setup, any interruption in the network connection can corrupt the file, and access by more than one user at the same time can also cause problems.
Power outages and surges
Like a system crash, an abrupt shutdown caused by a power cut or surge, or a forced shutdown because the system froze while Outlook was running, can seriously damage the PST file.
These events can sometimes cause irreparable damage to the PST file, leading to significant data loss.
To protect your computer against power cuts and surges, use an uninterruptible power supply (UPS).
If you use a laptop, keep an eye on the battery and keep the charger plugged in. If the battery is faulty, replace it as soon as possible.
Malicious software
Viruses and malware can get in when you open a malicious email, link or attachment received in Outlook.
A virus can also get in if you use a flash drive to move data between devices without scanning it first.
Viruses and malware can damage the PST file or encrypt its data, making it inaccessible and causing data loss.
To prevent PST corruption caused by viruses or malware, install reliable antivirus or anti-malware software with up-to-date definitions and real-time protection.
Also consider using cloud storage to transfer data. If you do use a drive for large files, scan the drive and the files before transferring them.
Abnormal Outlook shutdown
Outlook may crash or stop responding if the computer’s hardware isn’t powerful enough or if there is a problem retrieving some email items.
This happens because the application can’t finish a task, such as updating or processing the PST file, and stops responding to your commands.
In this situation, wait a while for Outlook to start responding again instead of forcing it to close.
After all, a .pst file can become corrupted if it is open when Outlook closes abnormally.
The same can happen if Outlook or Windows crashes, or if the computer is switched off without closing Outlook and shutting down Windows properly.
How to repair an Outlook Personal Folders (.pst) file
Repairing an Outlook Personal Folders (.pst) file takes 3 steps. Here are the details of each one.
Step 1 – Close Outlook and start the Inbox Repair Tool
To recover a PST file without losing data, start by making a copy of the .pst file in another location, so you always have the original to fall back on. Then run Microsoft’s Inbox Repair Tool (SCANPST.EXE).
To do this:
- Close Outlook and locate SCANPST.EXE in the Office installation folder (see the table below)
- Double-click SCANPST.EXE to run it (if Windows asks, confirm by selecting “Open” or “Run”)
- Follow the on-screen instructions
- After the “Inbox Repair Tool” has started, continue with Step 2.
To start the Inbox Repair Tool manually, open one of the folders below in File Explorer and double-click SCANPST.EXE.
The location of the file varies depending on your version of Outlook:
| Typical location | Notes |
| <disk drive>:\Program Files (x86)\Microsoft Office\root\Office16 | Outlook 2016 or later (Click-to-Run), 32-bit Office on 64-bit Windows |
| <disk drive>:\Program Files\Microsoft Office\root\Office16 | Outlook 2016 or later (Click-to-Run), 64-bit Office, or 32-bit Office on 32-bit Windows |
| <disk drive>:\Program Files (x86)\Microsoft Office\Office16 | Outlook 2016 (MSI installation), 32-bit Office on 64-bit Windows |
| <disk drive>:\Program Files\Microsoft Office\Office16 | Outlook 2016 (MSI installation), 64-bit Office, or 32-bit Office on 32-bit Windows |
| <disk drive>:\Program Files\Microsoft Office 15\root\Office15 | Outlook 2013 (Click-to-Run), 64-bit Office, or 32-bit Office on 32-bit Windows |
| <disk drive>:\Program Files (x86)\Microsoft Office 15\root\Office15 | Outlook 2013 (Click-to-Run), 32-bit Office on 64-bit Windows |
| <disk drive>:\Program Files\Microsoft Office\Office15 | Outlook 2013 (MSI installation), 64-bit Office, or 32-bit Office on 32-bit Windows |
| <disk drive>:\Program Files (x86)\Microsoft Office\Office15 | Outlook 2013 (MSI installation), 32-bit Office on 64-bit Windows |
| <disk drive>:\Program Files\Microsoft Office\Office14 | Outlook 2010, 64-bit Office, or 32-bit Office on 32-bit Windows |
| <disk drive>:\Program Files (x86)\Microsoft Office\Office14 | Outlook 2010, 32-bit Office on 64-bit Windows |
| <disk drive>:\Program Files\Microsoft Office\Office12 | Outlook 2007 on 32-bit Windows |
| <disk drive>:\Program Files (x86)\Microsoft Office\Office12 | Outlook 2007 on 64-bit Windows |
| <disk drive>:\Program Files\Common Files\System\Mapi\1033 | Another typical location (older versions) |
| <disk drive>:\Program Files\Common Files\System\MSMAPI\1033 | Another typical location (older versions) |
| <disk drive>:\Program Files\Common Files\System\Mapi\1033\NT | Another typical location (Windows NT and Windows 2000) |
| <disk drive>:\Program Files\Common Files\System\Mapi\1033\95 | Another typical location (Windows 95 and Windows 98) |
Step 2 – Repair the .pst file
In the Inbox Repair Tool, type the path and name of your Personal Folders (.pst) file, or select “Browse” to find it, and then select “Start”.
Note that you may need to run the Inbox Repair Tool several times to fully repair the .pst file.
Also, the Inbox Repair Tool may not fix every problem it finds.
In some cases, items cannot be recovered, for example if they were permanently deleted or are too badly corrupted for the tool to repair.
Step 3 – Recover repaired items in a new .pst file
After running the Inbox Repair Tool, you can start Outlook and recover the repaired items.
Optionally, you can also try to recover additional items from the backup file created by the tool.
- In short, you will create a new Personal Folders (.pst) file in your profile
- and then move the recovered items into this new .pst file. Here’s how:
- Start Outlook. If you use more than one profile, make sure you select the one that contains the .pst file you tried to repair
- Press Ctrl+6 to switch to the Folder List view
- In the Folder List, you should see a “Recovered Personal Folders” folder containing the default Outlook folders:
- These recovered folders are usually empty, because this is a rebuilt .pst file. You should also see a folder called “Lost and Found”, which contains the folders and items the Inbox Repair Tool managed to recover. Unfortunately, items that don’t appear there could not be recovered.
- Create a new Personal Folders (.pst) file in your profile. The steps vary depending on your version of Outlook.
Outlook 2010 and later
- Select the “File” tab on the ribbon and then “Info”
- Select “Account Settings” and then “Account Settings” again
- Select the “Data Files” tab
- Select “Add” to open the “Create or Open Outlook Data File” dialog box
- Enter a name for the new Outlook Data File (.pst) and select “OK”
You should now have a new Outlook Data File (.pst) in your profile.
Outlook 2007
- On the “File” menu, select “Data File Management”
- Select “Add” to open the “New Outlook Data File” dialog box
- In the “Types of storage” list, select “Office Outlook Personal Folders File (.pst)” and then “OK”
- In the “Create or Open Outlook Data File” dialog box, choose a location and a name for the new Personal Folders (.pst) file and select “OK”
- Select “OK” to finish
Once this is done, you should have a new Personal Folders (.pst) file in your profile.
Outlook 2003
- On the “File” menu, point to “New” and select “Outlook Data File”
- Select “OK” to open the “Create or Open Outlook Data File” dialog box
- Enter a name for the new Personal Folders (.pst) file and select “OK” to open the “Create Microsoft Personal Folders” dialog box
- Enter a display name for the new Personal Folders (.pst) file and select “OK”
You should now have a new Personal Folders (.pst) file in your profile.
Outlook 2002
- On the “File” menu, point to “New” and select “Personal Folders File (.pst)”
- Select “Create” to open the “Create Microsoft Personal Folders” dialog box
- Enter a display name for the new Personal Folders (.pst) file and select “OK”
- You should now have a new Personal Folders (.pst) file in your profile
- Drag the recovered items from the “Lost and Found” folder into the new Personal Folders (.pst) file
When you have finished moving all the items, you can remove the “Recovered Personal Folders” file, including the “Lost and Found” folder, from your profile.
Recover repaired items from the backup file
If you couldn’t open the original Personal Folders (.pst) file before running the Inbox Repair Tool, the following procedure may not work.
In that case, unfortunately, you won’t be able to recover any additional information this way.
If you could open the file, however, the following procedure may help you recover additional items from the damaged Personal Folders (.pst) file.
When you run the Inbox Repair Tool, the option “Make backup of scanned file before repairing” is selected by default.
This option creates a file on your disk called “filename.bak”. This file is a copy of the original .pst file with a different extension.
If items are still missing after following the steps in the previous section, try to recover additional information from this backup file as follows:
- Find the .bak file. It is in the same folder as the original Personal Folders (.pst) file
- Make a copy of the .bak file and rename the copy with a .pst extension, for example newname.pst
- Import the newname.pst file you created in the previous step using Outlook’s Import and Export Wizard. To do this:
- On the “File” menu, select “Import and Export” (in Outlook 2013 and later, select the “File” tab on the ribbon, then “Open & Export” and “Import/Export”; in Outlook 2010, select “File”, “Open” and “Import”)
- Select “Import from another program or file” and then “Next”
- Select “Outlook Data File (.pst)” (“Personal Folder File (.pst)” in older versions) and then “Next”
- Under “File to import”, select “Browse” and double-click the newname.pst file
- Under “Options”, select “Do not import duplicates” and then “Next”
- Under “Select the folder to import from”, select the top-level Personal Folders (.pst) folder and check “Include subfolders”
- Select “Import items into the same folder in” and choose your new Personal Folders (.pst) file
- Select “Finish”
Remember that the backup file is a copy of the original corrupted file, so you may not be able to recover anything beyond what already appeared in the “Lost and Found” folder.
If you can’t import the newname.pst file into Outlook, the information that isn’t in the “Lost and Found” folder can’t be recovered with Microsoft’s tools. A data recovery specialist may still be able to help.
How to recover corrupted PST files offline
To recover corrupted .pst files offline, you can use third-party recovery software such as Recovery Toolbox for Outlook. Always work on a copy of the .pst file, never on the original.
Follow the steps below:
- Download the program from the developer’s website
- Install it
- Run it and select the .pst file on the start page
- Choose the “Recovery Mode” option
- The contents of the .pst file will be displayed
- Select the folder where you want to save the recovered data and choose the “Save as PST file” mode
- Finally, click “Save”.
How to recover Outlook files online
The advantage of recovering Outlook files online is that it works across platforms, so you can use it from any device or operating system.
In addition, online services are usually more intuitive and don’t require you to install any software. Bear in mind, however, that you will be uploading all of your emails and contacts to a third-party server, so check the service’s privacy policy first.
Recovering .pst files online is simple. Just follow these steps:
- On the online Outlook recovery service’s website, select your Outlook data file (.pst or .ost)
- Enter your email address
- Select “Continue” and wait while the file is recovered
- Once the process is complete, download the package containing the recovered Microsoft Outlook .pst file.
Note that the online service saves the data recovered from corrupted files as a .pst file in the newer Microsoft Outlook format, which uses Unicode.
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Conclusion
A PST is a Personal Folders file created by Microsoft Outlook. It stores a user’s Outlook data, such as emails, tasks, contacts, calendar events and attachments, on the computer’s disk.
A PST file can be deleted, lost or corrupted for various reasons, such as viruses or malware, bad sectors and network problems.
It can also be damaged by a power cut or surge, or by Outlook closing abnormally.
To repair your .pst file, you can use Microsoft’s Inbox Repair Tool (SCANPST.EXE).
If that doesn’t work, the best option is to turn to a specialized data recovery service like Bot.
With more than 200,000 cases, our highly trained specialists are ready to recover your data quickly and safely.
When the disk itself is physically damaged, they work in a Class 100 (ISO 5) cleanroom, an environment where airborne particles are controlled, to increase the chances of recovering the data from your device.
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