If you are keeping 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, 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, 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)

 

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.

Note  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.

Repairing the .ost file

 

1. Close Outlook.
2. On the Start menu, click Run.
3. In the Open box, type

drive:\Program Files\Common Files\System\Mapi\LocaleID\scanost.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.
4. Click OK.
5. Click either Scan all folders or Choose folder to scan. If you click Scan all folders, this may take several minutes.
6. Select the Repair errors check box.
7. Click Begin Scan.