Outlook 2007 deployment .msp file

Microsoft Outlook updates change the default mail handler to Microsoft Outlook.

If you are prompted to install an update to Microsoft Outlook 2003 (such as updated junk mail filters) from Microsoft Update (or have your system set to automatically update), and if you have Microsoft Outlook 2003 installed, then when the update is installed, Microsoft Outlook is set as the default mail client, regardless of the previously set default mail client. This change is accomplished via the update changing the default registry value to "Outlook" under this registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail

If you allow the installation of such updates, it is not possible to prevent the change in the default mail client from the user's previously set value to Microsoft Outlook. Consequently, for Outlook Express (or other mail user agents) users who have Microsoft Outlook installed, but who have Outlook Express (or another program) set as their default mail client, that client will be changed to Microsoft Outlook after the installation.

There are two ways to workaround this issue:

1. Uninstall Microsoft Outlook 2003 via Control Panel | Add / Remove Programs. Select Microsoft Office and then click the change button and remove Microsoft Outlook. (Then do #2 below once.) That way you will not be subject to this issue occuring every single time a Microsoft Outlook update occurs.

2. Open Internet Explorer and go to Tools | Internet Options | Programs (or go to Control Panel | Internet Options | Programs) and change the default program to Outlook Express (or whatever your mail user agent program was prior to the update). That will change the registry key value back to what it was before. If that does not reset the default mail handler to the prior one, then you can also go to Start | Programs (or Control Panel | Add / Remove Programs) | Set Program Access and Defaults and then restore the default mail handler there. For Outlook Express, also see here: www.oehelp.com/oedef.aspx

Some may also need to follow the steps in this article:

"Send To" and E-mail Links Do Not Work Using Outlook Express as Default
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q306098

If Microsoft Outlook is still installed and updates are still permitted to be installed, the user will continue to have to perform this step after each update

Open the OCT;
setup.exe /admin
Navigate to Features
MS Office Outlook 2007
Other
Make Outlook the default program for E-mail, Contacts, and Calendar
Double-Click the above and select - Disabled.

You could also change the install option to - installed on first run.