You install Microsoft Office 2003 by using a custom transform (.mst file) that was created by using the Custom Installation Wizard for Office 2003. After you do this, you may receive the following error message when you start Microsoft Office Outlook 2003:
Unable to open your default e-mail folders
This issue may occur when the following conditions are true:
You are using Outlook 2003 in Cached Exchange Mode.
The custom transform creates a REG_SZ registry value for the
The custom transform uses an environment variable such as %userprofile%.
Note The Custom Installation Wizard for Office 2003 recommends that you use an environment variable.
Because the registry value is REG_SZ, Microsoft Windows cannot expand the environment variable.
To resolve this issue, modify the custom transform. To do this, follow these steps:
In the Custom Installation Wizard for Office 2003, disable the ForcePSTPath setting in the Change Office User Settings dialog box. This setting is located in the Microsoft Office Outlook 2003\Miscellaneous\PST Settings folder.
In the Add/Remove Registry Entries dialog box, click Add on the Add Registry Entry tab.
Type the following registry settings:
Root: HKEY_Current_UserData Type: REG_EXPAND_SZ
Value Name: ForcePSTPath
Value Data: userprofile\existing_folder_path
On the Outlook: Customize Default Profile page, click New, and then configure the profile to use Cached Exchange Mode.
Use this modified custom transform to reinstall Office 2003.