Personal Storage Table (PST/Outlook Data File), Personal Folder File (PFF)

PST File or Outlook Data File is the file storage facility developed by Microsoft Co. in order to keep entire Outlook data including Emails, Attachments, Contacts, Notes, Calendars items, Task, etc. PST File is constructed using Binary data file algorithm and at the logical level, it is divides into three different layers: NDB (Node Database), LTP & Messaging Layer.

This file format belongs to Database File category.

Microsoft Outlook

As stated above, Microsoft Co. is the creator of MS Outlook and all the pertained stuffs. As from 1997, the Outlook term has coined in the Tech world and since then there have been lots of upgrade seen in this email client in past decade.


hexadecimal: 21 42 44 4e

ANSI (97–2002 Personal Folder File)

Default file format for older versions of Outlook (97–2002) capable to hold data up to 2 GB, does not support multiple languages, structure is a 32–bit unsigned value. However, Outlook still provides an option to create ANSI PST file even in its latest versions of Outlook whilst creating a PST File.

UNICODE (2003 – 2016)

UNICODE (2003 - 2016) is multi-lingual data file format, 64-bit unsigned long, can handle data up to 50GB (massive amount of storage capacity), and cannot run in older version of Outlook (count as a drawback).

MS Outlook 2016

Outlook 2016: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\

MS Outlook 2013

Outlook 2013: HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\

MS Outlook 2010

Outlook 2010: HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\

MS Outlook 2007

Outlook 2007: HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\

MS Outlook 2003

Outlook 2003: HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\

Note: You can also find out the location of PST file using "Account Settings" option available in Microsoft Outlook's settings.

Outlook Error 0x800ccc78

This error does not allow user to send email and consequently even mail does not go out from your Outlook even after hitting on "Send/Receive" button so many times.

Cannot Start Microsoft Outlook (Outlook Does Not Start)

Such error encountered when a profile.xml file gets impaired. Actually, this profile is one of the staple subsidiary file, which help Outlook to run itself.

PST File is not an Outlook Data File

Sometimes Outlook does not show up any data of Outlook PST File Extension and in opposite just show error message "PST File is not an Outlook Data File". User also runs into this error when they attempt to import a PST File in Microsoft Outlook. According to experts, corrupted PST file is anticipated behind the cause of this error and aside from it, every odd discussion (including KB articles) on the web alluded about "scanpst.exe" to deal with this error.

Outlook Error 0x800ccc0f the connection to the server was interrupted

It also impedes the outgoing emails to move from your Outlook.

Outlook Error not Implemented

directly influence the sending/receiving of emails in Outlook and confined the application not to process email ahead. Restoring SRS (Send/Receive) file can helpful to overcome this error.