Posted on May 27, 2015 · Posted in MS Office

How to Repair a Corrupt Outlook PST File with Scanpst

Microsoft Outlook stores user data in OST and PST files. An OST file is a cached copy of a user mailbox that is stored on MS Exchange server. A PST file is a personal folders file containing email messages, calendar, tasks, and other items of user and stored locally on the PC. Sometimes Outlook PST files can become corrupted and cannot be opened in MS Outlook. If a user cannot open the mail archive in pst files, it becomes a headache for Hepldesk and administrators .

In this article we’ll talk about the main reasons why personal folders files get damaged and how to repair a damaged or corrupted Microsoft Outlook pst file using the Inbox repair tool.

The reasons why the archive files of personal folders in Outlook get damaged can be different. This can be a result of errors in the file system (in this case you should start with the file system check), damage of the PST file structure due to accidental closure of Outlook (it happens quite often), power failure, virus activity, storing PST files in the shared network folder (this configuration is not supported by Microsoft), etc.

In various versions of the Outlook  there are different restrictions on the maximum size of a PST file. If the file size is larger than the maximum size or when you try to open a large file in the old version of mail client, MS Outlook may not work properly. The restrictions to the size of PST files are as follows:

  • Outlook 2002 or earlier — PST files use the ANSI format and are limited to 2 GB
  • Outlook 2003 and Outlook 2007 files are limited to 20 GB
  • Outlook 2010 and Outlook 2013 PST/OST files use the Unicode format and are limited to 50 GB

Also you shouldn’t forget that the larger the file is, the more frequently the errors occur, so it is recommended to work with PST files no larger than 2-8 GB.

When a PST file is damaged, Outlook cannot open the file, returning this error, for instance:

Cannot start Microsoft Outlook. Cannot open the Outlook windows. The set of folders cannot be opened. Errors have been detected in the file ….outlook.pst

Cannot start Microsoft Outlook . The set of folders cannot be opened. Errors  in pst  file


The file …outlook.pst is not an Outlook data file (.pst)

The file pst file is not an Outlook data file (.pst)

If the similar errors occur, a PST file is damaged and its logical structure has to be repaired.

First of all, let’s find out where Outlook stores its PST files. By default, *.pst (personal folders) and *.ost (local cached copy of the Exchange server folders) files are stored in the following directories depending on the OS version:

  • Windows 2000, 2003, XP : C:\Documents and Settings\%username%\Local Settings\Application Data\Microsoft\Outlook
  • Windows Vista, Windows 7 and Windows 8 : C:\users\%username%\AppData\Local\Microsoft\Outlook

However, if necessary a user can create/move a personal folders file to any location.

Important! Before you repair a PST file, make a backup of this file. Thus you’ll prevent further damage of the file by a repair tool or Outlook itself.

To recover the damaged Outlook archive folders, Microsoft supplies a special Microsoft Outlook Inbox Repair Tool (scanpst.exe).This small tool is not an all-in-one remedy and doesn’t allow to repair a PST file with any damages, it rather helps to solve the majority of typical issues that may occur to personal folders files.

You can find this tool in the following directory:

c:\Program Files\Microsoft Office\OFFICE{Office version–11,12,13,14}

For example, in Office 2010 the path to the directory containing scanpst.exe can look like this:

C:\Program Files\Microsoft Office\OFFICE14

It doesn’t work for Outlook 2013, look for the tool in c:\Program Files\Microsoft Office 15\root\office15

Note. If you are using a 64-bit system, the path is as follows:

C:\Program Files (x86)\Microsoft Office\Office14

scanpst.exe for Outlook 2010

Let’s try to repair the damaged PST file automatically. To do it, start scanpst.exe and specify the path to the PST file.

Important! Before starting the tool, close Outlook and other processes using the PST file to be repaired.

To scan a file for errors, click Start.

scanpst.exe  - Microsoft Outlook Inbox Repair Tool

Validation and analysis of the file structure consists of 8 steps. The scan time depends on the size of your PST file and the number of errors in it.

Scanpst checking file consistency

In our case the tool has reported that the personal folders file contains some errors and suggests to repair it (the Repair button). If you haven’t made a backup of the PST file, you can do it now by checking the correspondent box and specifying the file name.

Backup and repair pst file

After you click Repair, the PST file repair starts, which also consists of 8 steps. In our case, it has taken 15 minutes to repair a 1GB archive.

If it goes ok, you’ll see the message Repair complete after the tool is done, and you can try to open the PST file in Outlook.

Repair complete

So, as we have told already, scanpst.exe helps in most cases (about 90%) when errors in PST file occur.

Scanpst not help if:

  1. PST file header is damaged
  2. PST file is protected with a password
  3. You have to recover email messages or folders deleted by mistake (you can recover deleted items on Exchange server)
  4. Exceeds the maximum size for PST file
  5. There are complex damages of the logical and/or physical file structure of your PST file


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