Updated: 2009-04-09

Upgrading to Microsoft Office Outlook 2007 typically involves planning for the upgrade, customizing settings, and then deploying Office Outlook 2007 on users' computers. The Outlook data file format in Office Outlook 2007 is compatible with earlier releases and you do not need to migrate data files.


This topic is for Outlook administrators. If you are experiencing difficulty upgrading Outlook on your computer, see Upgrade Your Installation in the Microsoft Office Outlook 2007 Help and Support page on Office Online.

Planning an upgrade

More information about planning an upgrade to Office Outlook 2007 is included in Plan an upgrade to Outlook 2007. The topic discusses the following items:

Issues to consider when planning an upgrade, including planning for cryptographic and security needs, Microsoft Exchange Server upgrades, and so on.

Upgrading from an earlier version of Outlook, including configuring Outlook user profiles, upgrading with Cached Exchange Mode already configured, upgrading from an Outlook Internet-only (IMO) installation, choosing fax support, and supporting forms.

Upgrading from other mail and scheduling programs, including a table that lists migration paths that are supported by Office Outlook 2007.

PST and OST files

With Office Outlook 2007, users can open and use Outlook data files that were created in earlier versions of Outlook. Users that have Outlook Offline (OST) files — for example, users configured to use Cached Exchange Mode — do not need to recreate those files. Similarly, users with Outlook Personal Folder (PST) files can continue to use the files without converting or migrating the files.

Outlook PST and OST files that are created by using Microsoft Office Outlook 2003 and later use the updated Unicode file format that allows larger file sizes (the 2 gigabyte limit is eliminated). The data file format used by Outlook 2002 and earlier is also supported by Office Outlook 2007.

There is no tool available to convert groups of previous PST and OST files to the newer format, but you can provide a procedure to your users for individual file update. The steps to convert data files are provided in Convert a non-Unicode data file (.pst) to a Unicode data file (.pst).

You can also configure settings that ensure that new files are created in the more current format. For more information about configuring and working with Unicode Outlook data files, see Configure Unicode options in Outlook 2007.

Download this book

This topic is included in the following downloadable book for easier reading and printing:

See the full list of available books at Office Resource Kit information.