What Is A .PST File?

In short, a .PST file is simply that - a single file with a .pst extension. What makes a .PST file special is the fact that Microsoft Outlook stores all of your information inside of a single .pst file. And if anything bad should ever happen to that file, such as getting deleted, getting damaged, or getting corrupted in any fashion, then you run the risk of losing all of your information. That includes any email messages you've received, contacts you've collected, calendar events you've scheduled, journal entries you've created, notes you've taken, tasks that need doing, etc. Anything you create or receive using Outlook gets stored in one, big PST file.

Depending on who you ask, PST stands for "Personal Storage Table" or "Personal Folders File". Microsoft Outlook stores its .pst file on your local hard drive. When Outlook retrieves an email message it removes it from the email server and stores it in its PST file. The more email you receive, the bigger your PST file gets. Many versions of Outlook (Outlook 97, Outlook 98, Outlook 2000, Outlook 2002) can't handle a PST file that gets bigger than 2GB in size. Once your .pst file gets that large you're in trouble as Outlook can no longer open the file and will act as if it is corrupted. (If you run into that situation, Stellar Outlook PST Repair can split pst files that are too big, solving the

Starting with Outlook 2003, PST files have a maximum size determined by the user, with a recommended upper limit of 20GB. Which is a good thing as the amount of email users receive and retain continues to go up. Unfortunately, file size limits are only one of the problems effecting the Personal Storage Table file used by Outlook. Because the PST file gets used quite heavily, it is vulnerable to corruption if anything gets written to it incorrectly or incompletely. So if Outlook crashes or shuts down incompletely or gets interrupted, or if your power fails or computer gets shut down improperly, or if another application is buggy or crashes, your Outlook PST file might get left in an improper, or corrupted, state. Outlook will report some error and will refuse to open the corrupt .pst file.

Just because Outlook cannot handle a corrupted .pst file doesn't mean all is lost. That's where a repair tool like Stellar Outlook PST Repair comes in handy. Stellar Outlook PST Repair was developed by Stellar Phoenix and is sold by Avanquest Software via the SafeCart shopping system. Stellar Phoenix is an award-winning company that specializes in data recovery software and services. They've been in business since 1993, so they have years of experience recovering data from all sorts of Microsoft applications. In fact, Microsoft doesn't have any comparable tool to repair PST files and would rather let others within the market provide these specialty tools.

You can learn more about PST files from the Wikipedia .pst entry and this Microsoft article about Outlook data files.