Repair pst or ost file in outlook

1. Open Windows Explorer and select the drive 
2. C:\Program Files\Microsoft Office\OFFICE14 folder.
3. Double-click Scanpst.exe.
5. 

1. In the Enter the name of the file you want to scan box, enter the name of the .pst or .ost file that you want to check, or click Browse to select the file.
2. To specify the scan log options, click Options, and then click the option that you want.
3. Click Start.
4. If errors are found, you are prompted to start the repair process to fix the errors.

A backup file is created during the repair process. To change the default name or location of this backup file, in the Enter name of backup file box, enter a new name, or click Browse to select the file that you want to use.

7. Click Repair.
8. Start Outlook with the profile that contains the .pst file that you tried to repair.
9. In the Navigation Pane, click Folder List.

Keyboard shortcut  To open switch to the Folder List, press CTRL+6.

In the Folder List, you might see a folder named Recovered Personal Folders that contains your default Outlook folders or a Lost and Found folder. The recovered folders are usually empty, because this is a rebuilt .pst file. The Lost and Found folder contains the folders and items recovered by the Inbox Repair tool.

You can create an Outlook Data File (.pst), and drag the items in the Lost and Found folder into the new data file. When you have finished moving all the items, you can remove the Recovered Personal Folders (.pst) file, including the Lost and Found folder, from your profile.