About data files

When you create messages, appointments, tasks, and journal entries, Microsoft Outlook saves the information in a data file on your computer. The data file is called a Personal Folders file because it is saved locally with a .pst file extension. The .pst file is the same as in previous versions and is compatible with Outlook 2000, 98, and 97.

If you use Microsoft Exchange Server, typically your e-mail messages, calendar, and other items are delivered to and stored on the server. If you don't use Microsoft Exchange Server, your e-mail messages, calendar, and other items are deliverd to and stored locally in a Personal Folders file called Outlook.pst. Outlook.pst is the default data file.

Use a data file to organize or back up items

You can create additional data files if you want to organize Outlook items into specific folders. For example, you might want to keep all messages from a specific company in a separate data file. When you create the data file, you can use any name for the file. The default name is Personal Folders(1).pst, Personal Folders(2).pst, and so forth. You can use any name for the folder associated with that data file. The default name for the folder that appears in the Outlook Folder List is Personal Folders.
You can also use AutoArchive to move items to a an archive file (Archive.pst. Unlike exporting, where the original items are copied to the export file but are not removed from the current folder, archiving copies items to the archive file and then removes them from the current folder. AutoArchive allows you to set up a schedule and archive multiple folders at the same time at set intervals.
A utility called PST Backup enables you to make an exact copy (in the same file format) of a .pst data file, copy the backup file to your hard disk or to a network share, and specify a time interval at which Outlook will prompt you to back up a file. Use the backup file to restore the current .pst file in the event that it becomes corrupted or deleted. To use the utility, you must download it from the Microsoft Outlook downloads site.
When you remove items from a Personal Folders file, your file size will not decrease unless you Compact the file. For more information, see the topic "Reduce the size of a data file."

Use a data file to distribute information

You can use a data file to make information, such as Contacts, available to another computer you use or to people you work with. The easiest way to do this is to export (copy) the information to a .pst file using the Import/Export Wizard.

Data file locations

To see where default store and additional data files are kept on different versions of Microsoft Windows, see the "Outlook file locations" topic. Keep these points in mind:

You can save, copy, and move a data file (other than the file used as your default information store) to another location on your hard disk, to a floppy disk, or to a share on the network. But remember that you must have read/write permissions to open Personal Folders files (.pst) from a network share.
If you need to access any data file that is stored on a network share or on another computer, close any program that might be using that file. A data file can be accessed by only one user or program at a time.
The .pst data file does not support read-only media.
Only data files that you created will appear in the Outlook Data Files dialog box (File menu, Data File Management command). Your default data file, Outlook.pst, does not appear in the list.

Data file security

When you create a .pst, you can assign a password to the file. Even if you select the Save this password in your password list check box, make a note of the password in case you use the .pst on another computer.