A PST file is a so-called Personal Storage Table, ie a storage for personal data. PST is a proprietary but open format used by Microsoft Outlook and Microsoft Exchange to manage contact information. Microsoft Outlook is a contact manager and part of Microsoft Office. Pst files are data containers that contain, among other things, emails, addresses, calendar data and tasks.
In addition to a standard PST file, Outlook can also manage multiple PST files. Since there are always problems with corrupt PST files, it is recommended to create backups regularly, taking into account that, among other things, account and program settings are not saved in the PST file. To repair defective PST files, the program scanpst is installed with Outlook.
The maximum file size of a PST file can now (from Outlook 2003) be up to 20 GB, before that it was only 2 GB. Very large PST files can cause Outlook to slow down noticeably. Defragmenting the hard disk or archiving old emails can help here.
The free Outlook Express does not use PST files but can import them. Since the PST format is open, other mail programs can also import PST files, for example Thunderbird. Since the PST format has meanwhile been changed several times, problems can occur during import. Unfortunately, most programs rely on Outlook being installed to import a .pst file.
Most often resolving problems with opening PST files is very simple. Just install an appropriate program that supports such files. All of the listed programs support PST files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of PST files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate PST files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Outlook applications is not on the list, select "Browse" option in order to manually locate the directory where Outlook has been installed.
Sometimes problems with opening PST files may not lie with the application itself, but can arise due to other causes, such as: