Using the Inbox Repair Tool (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;

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>.

Additional often seen variants are;

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), Outlook crashing upon displaying a folder or writing data to it, mspst.dll errors in the Event Viewer, import/export not completing, 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 Inbox Repair Tool fails and how to prevent pst-file corruptions from happening in the future.

  • Locating scanpst.exe for your Outlook version
  • Running the repair process
    • Locating the pst-file
    • Starting the scanning process
    • Starting the repair process
    • Repair completed
  • Repair process failed
  • Other issues with pst-files
    • Repairing a pst-file around 1.8GB in size
    • CRC errors reported when trying to copy pst-file
    • Pst-file is in use
    • Inbox Repair Tool does not recognize the file
    • Lost and Found folder
  • Prevent pst-file corruptions
  • Additional screenshots of error messages

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.
When using 2002/XP or 2003, then the location also depends on your installed language of Office; <locale ID>. For instance, for the US English version this is 1033.

Outlook 2016
32-bit Windows; C:\Program Files\Microsoft Office\Office16\
64-bit Windows; C:\Program Files (x86)\Microsoft Office\Office16\
64-bit Outlook;   C:\Program Files\Microsoft Office\Office16\

Office 365 / Outlook 2016 Click to Run
any Windows; C:\Program Files\Microsoft Office\root\office16\

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

Office 365 / Outlook 2013 Click to Run
any Windows; C:\Program Files\Microsoft Office\root\office15\

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

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

Outlook 2003
32-bit Windows; C:\Program Files\Common Files\System\MSMAPI\<locale ID>\
64-bit Windows; C:\Program Files (x86)\Common Files\System\MSMAPI\<locale ID>\

Outlook 2002/XP
C:\Program Files\Common Files\System\MAPI\<locale ID>\

Outlook 2010 – Click-to-Run
When you use a Click-to-Run version of Outlook 2010, then you will not be able to open scanpst.exe via conventional means. Instead, follow the following procedure;

  1. Open the Click-to-Run version of Word, Excel or PowerPoint.
  2. Choose File-> Open
  3. Browse to the following location;
  4. Set the “All Word Documents” drop down list list to “All Files”.
  5. Right click on scanpst.exe and choose Open.

The folder <14####.lan> is a variable that depends on the version and language of your Click-to-Run installation. For instance; 140062.enu

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;

Windows XP

  • Outlook 2007 and previous
    C:\Documents and Settings\%username%\Local Settings\Application Data\Microsoft\Outlook\
  • Outlook 2010
    C:\Documents and Settings\%username%\My Documents\Outlook Files\

Windows Vista, Windows 7, Windows 8 and Windows 10

  • Outlook 2007 and previous
  • Outlook 2010, Outlook 2013 and Outlook 2016
    C:\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…

The “Local Settings” and “AppData” folders are hidden folders. 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.

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;

  • DataNumen Advanced Outlook Repair (discount code: DNC-PUXB-HT )
  • Cimaware OutlookFIX
  • Stellar Phoenix Outlook PST Repair
  • 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.

Other issues with pst-files

There can be several other issues with pst-files which you can run into. The most common are posted below together with their solution.

Repairing a pst-file around 1.8GB in size

If your pst-file is around 1.8GB in size and Outlook refuses to open it or to write to it then it is quite likely that you are using an ANSI formatted pst-file. This file format was the default (and only) file format in in Outlook 2002/XP and previous and has a file size limit of around 1.8GB.

While the new pst-file format (Unicode) in Outlook 2003 and later versions of Outlook no longer have this limit, the limit still exists if you are using an older pst-file.

If you can still open the pst-file in Outlook, then it is recommended to copy the contents to a new Unicode pst-file.
If you can no longer open the file in Outlook, then you must use the pst2gb tool to truncate the pst-file first.

More info:
Am I in ANSI or UNICODE format?
Migrate from ANSI to Unicode
PST2GB: Oversized PST and OST crop tool

CRC errors

When you get CRC errors upon trying to copy the pst-file in Explorer or open it in Outlook, you usually have a failing hard disk which should be dealt with immediately. For instructions see; CRC (Cyclic Redundancy Check) errors on pst-file

Pst-file in use

When you get a pst-file in use error, it means that Outlook is still running or another application which integrates itself with Outlook or depends on the outlook.exe process is still running. A quick fix might be to simply restart your computer. To troubleshoot this issue further see; Outlook doesn’t close.

The file <path to pst-file> is in use by another application. Close Microsoft Outlook and all other mail-enabled applications, and try again.

Inbox Repair Tool does not recognize the file

In this case you have either selected a file which isn’t a pst-file or a file that is too badly damaged for scanpst.exe to repair. In case of the last, you can try a 3rd party recovery tool. However, if the file is smaller than 265KB then it means that the file is empty and nothing is in there to recover.

The Microsoft Outlook Inbox Repair Tools does not recognize the file <path to pst-file>. No information can be recovered.

Lost and Found folder

The Lost and Found folder is created during a repair when items have been found for which it was impossible to determine their original folder or when the folder structure within the pst-file got lost completely.

When such a corruption in a pst-file exists, it is highly recommended to start with a new pst-file and copy over the recovered contents to that pst-file. This process is similar as in; Scanpst.exe keeps finding issues

Prevent pst-file corruptions

Prevent buttonPreventing is better than repairing of course. While there have been a lot of precautions built into Outlook to prevent pst-file corruptions, there are a couple of common causes which may result in corruptions in the pst-file;

  • Computer/Outlook crashes
    If your computer crashes while Outlook was running or even worse, writing data to your pst-file, running scanpst.exe afterwards is highly recommended. Always try to find the root cause of your computer crashes and make frequent backups of your pst-file when you cannot directly find the cause (actually, making backups frequently is always recommended).
  • Outlook not closing properly
    If Outlook doesn’t close properly (the outlook.exe process continues to run after you close Outlook), then Outlook will be closed forcefully when shutting down your PC which is similar to Outlook crashing. To troubleshoot see; Outlook doesn’t close
  • Faulty add-ins which write corrupted data
    While add-ins are great to extend the functionality of Outlook, they might not all work as expected. If corruptions continue to occur in your pst-file, it might be good to review your installed add-ins and see if you still need them or if an update is available. You might be even using some without knowing. Disable them all and see if the corruptions return. If not, test them one-by-one to find the culprit. For more info see; Enable/Disable add-ins
  • Storing your pst-file on a network share
    Pst-files are designed to work from a local hard drive. Using pst-files from a network share is not supported by Microsoft and could lead to poor performance, data corruption or even data loss.
    If you are using Outlook 2010 and have your My Documents folder redirected to a network share, you might be using your pst-file from a network share without realizing it.

Additional screenshots of error messages

Below you’ll find several screenshots of errors which Outlook might display when there is an issue with your pst-file.

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>.

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>. Quit Outlook and all mail-enabled applications and then use the Inbox repair tool (Scanpst.exe) to diagnose and repair errors in the file. For more information about the Inbox repair tool, see Help.

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

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