Outlook PST files can become corrupted

Outlook PST files can become damaged — and when this happens, work grinds stop. If your company relies on Outlook, one of these software could save the day.

Outlook is the industry standard groupware tool. Organizations depend on it for email, attachments, tasks, contacts, calendaring, ... it is often the heart and soul of a business. However, the file that contains the precious data for Outlook is a fragile one, and when it breaks it can be a nightmare to repair. Fortunately, plenty of tools out there can help keep the integrity of that data file intact. Which ones are the most reliable and safe to use? Which ones will bring the file back from the dead? Let's take a look at five that can effectively tackle the task.

Note: Always back up your data file before using any tool on it.

1: Built-in cleaner: Scanpst

Outlook has a built-in PST cleaner called Scanpst. It's not the tool you will use when a PST file is really broken, but it's one of the most reliable for smaller issues. I have used this tool more than any other, mostly because I know it won't completely fubar a PST file. You generally wind up having to run Scanpst more than once to get the data file completely clean. I've used it up to five times on a PST file before it will come up with zero errors. But it works.

Using the Inbox Repair Tool (scanpst.exe)

SCANPST.EXE :- The Inbox Repair Tool is your first-aid-kit when it comes down to corruptions in your Outlook’s data storage file (pst-file).

A common need for running this tool is when Outlook refuses to load or is not willing to open a pst-file and displays an error similar to;

Something is wrong with one of your data files and Outlook needs to close. Outlook might be able to fix your file. Click OK --> run the Inbox Repair Tool.

Additional often seen variants are;

Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened.

Errors have been detected in the file <path to pst-file>

The file <path to pst-file> is not an Outlook data file (.pst)

In other cases, you might get recommended to use this tool when you are suffering from some specific symptoms such as (but not limited to), import/export not completing, mspst.dll errors in the Event Viewer, Outlook crashing upon displaying a folder or writing data to it, several send/receive errors or view settings not being maintained.

This guide helps you locate the Inbox Repair Tool for your version of Outlook, walks you through the repair process and gives recommendations what to do to when the Scanpst Tool fails and how to prevent pst-file corruptions from happening in the future.

Step 1: Locating scanpst.exe for your Outlook version
The location of scanpst.exe depends on your version of Outlook and whether or not you are using a 64-bit version of Windows.

Office 365 / Outlook 2019 / Outlook 2016 Click to Run

any Windows; drive:\Program Files\Microsoft Office\root\office16\

Outlook 2016 (MSI-based Volume License installation)
32-bit Windows; drive:\Program Files\Microsoft Office\Office16\
64-bit Windows; drive:\Program Files (x86)\Microsoft Office\Office16\
64-bit Outlook;   drive:\Program Files\Microsoft Office\Office16\

Outlook 2013
32-bit Windows; drive:\Program Files\Microsoft Office\Office15\
64-bit Windows; drive:\Program Files (x86)\Microsoft Office\Office15\
64-bit Outlook;   drive:\Program Files\Microsoft Office\Office15\

Outlook 2013 Click to Run
any Windows; drive:\Program Files\Microsoft Office\root\office15\

Outlook 2010
32-bit Windows; drive:\Program Files\Microsoft Office\Office14\
64-bit Windows; drive:\Program Files (x86)\Microsoft Office\Office14\
64-bit Outlook;   drive:\Program Files\Microsoft Office\Office14\

Outlook 2007
32-bit Windows; drive:\Program Files\Microsoft Office\Office12\
64-bit Windows; drive:\Program Files (x86)\Microsoft Office\Office12\

Running the repair process
The repair process consists out of several steps. If you already know the location of the pst-file that you would like to scan, continue to; Starting the scanning process

Step 1: Locating the pst-file
When you start the Inbox Repair Tool (scanpst.exe), the first thing it prompts you for is the location of the pst-file to scan. This path is revealed in the startup error or otherwise the default locations are as follows;

• Outlook 2007 and previous
  drive:\Users\%username%\AppData\Local\Microsoft\Outlook\
• Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019 and Office 365
  drive:\Users\%username%\Documents\Outlook Files\

Another way to determine the location of your pst-file (in case it differs from the default location) is via the Mail applet in Control Panel-> button Data Files…
If you have multiple profiles and the pst-file to scan is not part of your default mail profile, press the Show Profiles… button to select the correct profile first and the Properties…

Note:
The “AppData” folder is a hidden folder. To access these folders, you can type the path in the Address Bar or File Name field of the Explorer dialog that opens when pressing Browse…

Microsoft Outlook Inbox Repair Tool (scanpst.exe)

The Inbox Repair Tool (scanpst.exe) with a file selected to scan.

Step 2: Starting the scanning process
After you have selected the pst-file to scan, you can press the Start button. At this point, nothing will happen to your pst-file yet; scanpst will do an analysis first. This analysis consists out of 8 phases of which some can take quite a bit longer to complete than others depending on the size and level of corruption of the file.

scanpst.exe - Checking file consistency
Analysis in progress…

After the analysis scan has completed, it will present you with a scanning report and options for the next step. You can press the Details… button for more information about the type of corruption.

scanpst.exe - Errors were found in this file
Errors were found but you are almost ready to repair them.

Step 3: Starting the repair process
Before you continue to the actual repair process, make sure you have a backup of the pst-file. If you do not have a backup already, make sure that you have the option set to make a backup before proceeding (selected by default).

After pressing the Repair button, the actual repair process will start and go through the 8 phases again. With a very large pst-file (larger than 4GB) and a slower hard disk, this process can sometimes take longer than half an hour.

Note:
When the repair process starts, it could appear that it will hang directly (Not Responding in Title Bar). In reality, it is not hanging but making a copy of your pst-file in the background or already has started the repair process. Depending on the size of your pst-file and the speed of your hard disk, this can take a while.

Microsoft Outlook Inbox Repair Tool (Not Responding)

If it still hangs after 10 minutes (no hard disk activity either) and still hasn’t begun the actual repair process, you might want to abort the scanpst.exe process via Task manager

CTRL+SHIFT+ESC –> select tab Processes

Then, make a copy of your pst-file manually and restart the Repair process but this time with the Backup option disabled. If it still fails then, continue to the Repair process failed section.

Step 4: Repair completed
If everything goes correctly, you’ll get the “Repair complete” dialog after some time. You can then press OK to close it and start Outlook again.

If everything works now; you’re done but you might want to read the Prevent pst-file corruptions section anyway ;).

scanpst.exe - Repair complete

Repair process failed
If the repair process fails, try running it again. If it fails repeatedly, but you can still access the file in Outlook, you can create a new pst-file in Outlook and copy over its contents. For step-by-step instructions see; Scanpst.exe keeps finding issues

If you can no longer access the pst-file in Outlook and the pst-file is beyond repair for the Inbox Repair Tool, you’ll have to restore it from backup or use a 3rd party recovery tool. An exception can exist if you are using an ANSI formatted pst-file and the file is around 1.8GB in size.

Tool Tips!
Popular data recovery tools for Outlook are;

Stellar Repair for Outlook
Kernel for Outlook PST Repair
Use their trial versions first to determine if they can recover more data from your pst-file than scanpst.exe.