Microsoft provides Scanpst, also known as the Inbox Repair Tool, for correcting most problems with damaged Personal Folders .pst files.

Before you can use scanpst, you need to find it. Microsoft doesn't add a shortcut for it to the Start menu so you'll need to look for it. The easiest way to access it in current versions of Office is by holding down Shift as you right-click on any Office app icon pinned to the Taskbar and choosing Open File Location. You won't see this option on the context menu if the app is open though, but since all Office .exes are in one folder, you can Shift + right-click on any Office app icon (Word, Excel, etc). Type S on the keyboard to jump to it (Press S there times if you use Word or Publisher shortcuts to open File Explorer.)

If you don't see Open File Location, you'll need to go into File Explorer and find scanpst yourself.

Open File Explorer then browse to C:\Program Files (x86)\Microsoft Office if you use 32-bit Office on 64-bit Windows or C:\Program Files\Microsoft Office if Office and Windows are the same bitness then type scanpst in the search field to find it. With Outlook 2013 and 2016, most users will find it at C:\Program Files (x86)\Microsoft Office\root\Office*, which is the location for click-to-run installs

If you are using a Windows Store version of Office (currently being shipped pre-installed on many new computers), scanpst can be found in a path similar to C:\Program Files\WindowsApps\Microsoft.Office.Desktop.Outlook_16010.9001.2171.0_x86__8wekyb3d8bbwe\Office16. (The version number will vary with your installed version.)

You will need to know the location of the .pst file that you want to repair. If you can open Outlook, you can get the pst location from the File, Data File Management screen. Select the pst file and click the Open Folder button.

Outlook 2010 and newer use the locations below for IMAP data files while the default location for POP3 pst files is in My Documents\Outlook Files.

Note: IMAP caches a copy of messages to the local computer and I recommend that you delete the IMAP data file. When you restart Outlook, it will rebuild the data file. This is generally better than trying to repair it using Scanpst or a commercial tool.

If you use Outlook 2007 or older and the pst file is in the default folder location, you can find it in the following locations:

Windows 7/8 or Vista:

C:\Users\username\AppData\Local\Microsoft\Outlook

Type or paste this shortcut in the scanpst dialog to jump to the location:

%localappdata%\Microsoft\Outlook

Windows XP or Windows 2000:

C:\Documents and Settings\username\Local Settings\Application Data\Microsoft\Outlook

Type or paste this shortcut in the scanpst dialog to jump to the location:

%USERPROFILE%\Local Settings\Application Data\Microsoft\Outlook

See Outlook Backup and Dual-Boot for additional information on file locations and ways to determine the location of a .pst file that you can see in Outlook.

See How to use Scanpst.exe to repair Outlook data files if you need Step-by-step instructions for Scanpst.

Usage | Notes | Tools | More Information

Usage

When you run Scanpst.exe, it performs a number of tests. If it finds errors, it asks whether you want to make a backup copy of the original file (always say Yes), then tries to correct the errors.

If you run Scanpst.exe against a .pst file that Outlook 2003 created for a local copy of Windows SharePoint Services events and contacts lists, you will get an error message that you can ignore. See You Receive an Error Message When You Use the Inbox Repair Tool to Scan a .pst File

For seriously corrupted PST files, try running Scandisk.exe (look under Programs | Accessories | System Tools) first, then Scanpst.exe, repeating 3-4 times until neither program returns an error. We've known this technique to restore data that the user thought was lost forever.

And if that doesn't do it, you can try our tips to repair a 2gb Personal Folders file or Offline Folders in Microsoft Outlook.

If the file is on an NTFS volume, you can't use Scandisk.exe so easily. One approach is to open the drive in My Computer and use the Tools menu commands to scan the disk. You may need to restart Windows for the scan to run.

Notes

While you can use Scanpst.exe on offline folder (.ost) files used for cached or offline access to Exchange Server folders, we recommend deleting the ost file and letting Outlook recreate it. It's generally faster to resync the data than it is to repair the ost and a new ost file results in fewer problems. If do use try to repair an OST file and it's corrupted beyond the ability of Scanpst.exe to repair it, delete the ost. When you reopen Outlook it will make a new ost file.

There may be cases where you need to run both ScanPST and PST2GB. See OL2000 Error Message When You Start Outlook 2000 or Try to Open a Personal Folders File.

Another approach is to use a hex editor remove a single byte from the middle of the PST file, then run Scanpst. A hex editor is a tool for editing raw files; every Windows shareware site has several to choose from. Eugene McCarthy of FAO Headquarters in Rome recommends the free iHex editor, which loads only 64kb of the file at a time, making it ideal for tinkering with extremely large PST files. For simple Scanpst repairs, Eugene recommends changing the first byte of the PST file from hex 21 to 00.

There is no comparable program for cleaning up corrupted Personal Address Book (.pab) files. You may be able to view and recover PAB data by opening the file with a hex editor.