A corrupted PST file is one of the most common issues. It may become evident that the data file is damaged if Outlook can’t open a message or several folders. Microsoft has recognized this issue and offers an Inbox Repair Tool (scanpst.exe) that will repair the existing errors in small 32-bit PST files. There is no need to download the application. Open it by clicking Start > Search > type in Scanpst.exe. Click to launch it, and browse for the file to repair. If you have a modern version of Outlook installed you need to use another program that will allow you to recover your PST file.