PST File

PST File stands for Personal Storage table. It is used by Microsoft Outlook to store all the information associated with the Outlook profile. It contains many folders, each of which has data related to Outlook attributes like emails, contacts, calendars etc. The default folders contained in an Outlook PST file are inbox, Drafts, Outbox, Sent Items, Deleted items, junk emails and search folders (from Outlook 2003), RSS Feeds (from Outlook 2007), Calendar, Contacts, suggested contacts (from Outlook 2010), tasks, notes and journals etc. the PST file uses .pst extension to save the files.

As soon as an Outlook account is created, Microsoft Outlook will automatically generate a PST file and links it with the created account. A single Outlook account can have any number of PST file. If needed one can import several Outlook PST files using the “Import Export Wizard”, which is available on outlook File menu. If there are multiple PST files, Outlook uses one of them to save the Outlook items. PST files can be secured with a password in order to restrict the unauthorized access.

MIME types: application/vnd.ms-outlook

Maximum size of a PST file:

  • From Outlook 2000 to Outlook 2002 used ANSI format and the maximum size is 2 GB
  • From Outlook 2003 to Outlook 2007, Unicode format was used to store data and hence the size limit was  20 GB
  • In Outlook 2010 the size limit increased to 50 GB

More the number of Outlook items, the larger the size of the PST file will be. Hence, you can create multiple files and store your Outlook items in case the size exceeds.

Location of a PST File:

Based on the Outlook and Windows OS versions, the default location of the PST file changes, the summarized and most commonly found locations are:

  • Outlook 2007 PST files location on Windows XP and its earlier version is: 
    C:\Documents and Settings\%username%\Local Settings\Application Data\Microsoft\Outlook\
  • Outlook 2007 PST files location on Windows 7 or Windows Vista is:  
    C:\Users\%username%\AppData\Local\Microsoft\Outlook\
  • Outlook 2010 PST file location on Windows XP :  
    C:\Documents and Settings\%username%\My Documents\Outlook Files
  • Outlook 2010 PST file location on Windows Vista or Windows 7 :  
    C:\Users\%username%\Documents\Outlook Files

Opening a PST file:

To open a PST file just go to File -> Tools -> Outlook Data File.
If the PST file is backed up, copy the PST file back to the hard drive and check whether “Read-Only” option is enabled or not. If yes, then change it to “Read and Write”.

Delete an Outlook PST File:

To remove a PST file, do not delete the file directly; this will lead to Outlook errors. First, it should be disconnected, removed or closed from the Outlook. After removing it from the Outlook, release the lock and then delete it safely.

  • Close the PST file: Right click the root folder and select “Close <name of the file>”
  • To remove the opened PST file: Data files list and select the PST file to be disconnected and click on Remove button

After which just go to its location and delete the PST file.

Note: You cannot remove or disconnect the PST file which is marked as default and also the PST files which are still associated with an email account.

There are also situations, where the PST file may get corrupt due to plenty of reasons like virus corruption, improper closing of the application etc. So in such situations, the only way to save your Outlook profile is by fixing the corrupt pst file. To know the details on how to do it, click here.