If you are keeping Microsoft Outlook® data on your computer, you are using a Personal Folders file (.pst) or an Offline Folder file (.ost). To prevent data loss, you need to know how to repair these files. If your .pst file becomes damaged, Outlook includes a tool that may be able to correct the problem without your switching to a backup copy. This tool, the Inbox Repair Tool ScanPST, is installed on your hard disk when you install Outlook. If your .ost file becomes damaged, Outlook includes a tool that may be able to correct the problem. This tool, the OST Integrity Tool ScanOST, can scan and repair .ost files. If that doesn't completely solve the problem, you can disable the .ost file and create a new one.

Repairing a Personal Folders file (.pst)

You may need to use the Inbox Repair Tool if you open your Outlook .pst file and receive this message: Unable to expand the folder. The set of folders could not be opened. Errors could have been detected in the file drive:\Documents and Settings\user\Local Settings\Application Data\Microsoft\Outlook\Outlook.pst. Quit all mail-enabled applications, and then use the Inbox Repair Tool. Huomautus The path to the file specified in the message may vary depending upon the operating system you are using on your computer.

If scanpst fails then you can use our Kernel for outlook tool to repair your corrupted pst mailbox files. To convert the ost file to a pst you can try our Kernel for OST.  

To Repair the .pst File

1. On the Start menu, click Run.
2. In the Open box,
   Type drive:\Program Files\Common Files\System\Mapi\LocaleID\scanpst.exe where LocaleID is the locale identifier (LCID) for your installation of Microsoft Office. For example, the LCID for English (United States) is 1033. For a list of LCIDs, see Microsoft Office Help.
3. Click OK.
4. In the Enter the name of the file you want to scan box, type the path and file name given in the error message above. Huomautus You may not be able to use the Browse button to locate this file because it is located in a hidden folder.
5. To change the options for logging errors during the scan, click Options. If you choose Replace log or Append to log, the log file is saved to the same directory as the .pst file.
6. Click Start.
7. When the file scan is completed, select the Make a backup of scanned file before repairing check box.
8. Click Repair.