Start Outlook 2010.
Click the File tab in the Ribbon, and then click the Info tab on the menu.
Click the Account Settings tab.
Click Account Settings again.
Click Data Files.

Note the path and file name of your .pst file. For example, C:\Exchange\Mailbox.pst indicates a .pst file that is named Mailbox.pst and is located in the Exchange folder on your drive C.
Click Close, click OK, and then click Exit and Log Off on the