Inbox Repair tool

If you can't open your Personal Folders file (.pst) or your Offline Folder file (.ost), or you suspect that your .pst or .ost data file is corrupted, you can use the Inbox Repair tool (Scanpst.exe) to diagnose and repair errors in the file. The Inbox Repair tool scans only the .pst or .ost file, not your mailbox on the server running Microsoft Exchange. The tool determines whether the file structure is intact. If it is not intact, the Inbox Repair tool resets your file structure and rebuilds the headers.

The Inbox Repair tool works on both the Microsoft Outlook 97-2002 Personal Folders File (.pst) and the Office Outlook Personal Folders File (.pst) data files in Microsoft Office Outlook 2003 and Microsoft Office Outlook 2007.

Scanpst.exe

Scanpst.exe is a free utility from Microsoft designed to repair corrupt or damaged Outlook PST files. You can look for a free scanpst.exe download, but that isn’t very safe as you never know what kind of file you might be getting from the Internet. And it isn’t necessary. Every version of Outlook, including XP, 2000, 2003, 2007, etc. (even the latest Microsoft Outlook 2010) includes a copy of the “Inbox Repair Tool”, which is the name for the scanpst.exe software program.

The problem is that the Microsoft Office/Outlook installer places the repair program in hard-to-find locations and makes it a hidden file. So make sure you search all your system files and you should be able to find it (more details on this below).
Scanpst.exe Errors