An earlier version of Outlook is removed and the newer version is installed unexpectedly

  • Article
  • Applies to:
    Office Home and Student 2010, Office Home and Business 2010, Office Standard 2010, Office Professional 2010, Office Professional Plus 2010

Symptoms

For a side-by-side installation, you install an original release non-trial version of one of the Microsoft Office 2010 suite or the 2007 Microsoft Office suite or suites that are listed in this article. If an earlier version of Office is currently installed, and the option to keep the earlier Office version is selected, the earlier version of Microsoft Office Outlook is removed, and Outlook 2007 or Outlook 2010 is installed unexpectedly.

This behavior occurs even though you select the option in the Setup program to keep all earlier versions.

Cause

This behavior occurs because two versions of Outlook cannot coexist.

If you select the option in the Setup program to keep all earlier versions of an original release non-trial version of an Office suite, the earlier versions of the Office programs are not removed. However, the earlier version of Outlook is removed. The 2010 and 2007 versions of the Office programs, except for Outlook, are installed to coexist with earlier versions of the Office programs. By default, the earlier version of Outlook is removed because two versions of Outlook cannot coexist.

Resolution

To resolve this behavior, use one of the following methods, as appropriate for your situation.

  • If you want to keep the earlier version of Outlook, and you have not installed the original release non-trial version of a 2010 or 2007 Office suite, follow these steps:

    1. Start the 2010 or 2007 Office suite Setup program.
    2. Select Customize.
    3. On the Upgrade tab, select Keep all previous versions.
    4. Select the Installation Options tab.
    5. Select the icon for Microsoft Office Outlook, and then select Not Available.
    6. Select Continue.

  • If you want to keep the earlier version of Outlook after you have installed the original release non-trial version of a 2010 or 2007 Office suite, follow these steps.

    Note

    These steps will remove Outlook 2010 or Outlook 2007 and reinstall the earlier version of Outlook.

    1. Select Start, select Control Panel, and then select Add or Remove Programs.
    2. Select the original release non-trial version of the 2010 or 2007 Office suite that is installed in the Currently installed programs list, and then select Change.
    3. Select Add or Remove Features, and then select Continue.
    4. On the Installation Options tab, select the icon for Microsoft Office Outlook, and then select Not Available.
    5. Select Continue.
    6. After the 2010 or 2007 Office suite Setup program has successfully completed and Outlook 2010 or Outlook 2007 is removed, follow these steps to reinstall the earlier version of Outlook:
      1. Select Start, select Control Panel, and then select Add or Remove Programs.
      2. Select to select the earlier version of Office in the Currently installed programs list, and then select Change.
      3. Select Add or Remove Features, and then select Next.
      4. Select to select the Outlook check box, and then select Update.
    7. After the Setup program for the earlier version of Office has successfully completed, and the earlier version of Outlook is reinstalled, follow these steps to repair the original release non-trial version of the 2010 select 2007 Office suite:
      1. Select Start, select Control Panel, and then select Add or Remove Programs.
      2. Select the original release non-trial version of the 2010 or 2007 Office suite that is installed in the Currently installed programs list, and then select Change.
      3. Select Repair, and then select Continue.

More information

When you upgrade to a 2010 or 2007 Office suite, and you select the option to keep all earlier versions, you may notice the following message on the Upgrade tab of the Setup program:

Before you install Outlook 2010 or 2007, you must remove any earlier version of Outlook. Two versions of Outlook cannot coexist on the same computer. If you want to keep an earlier version of Outlook, you must explicitly choose on the Installation Options tab to not install Microsoft Office Outlook 2010 or 2007.

This message may be misleading because you do not have to remove an earlier version of Outlook before you install Outlook 2010 or Outlook 2007. When Outlook 2010 or Outlook 2007 is installed, the earlier version of Outlook is removed automatically.

If you install and then uninstall Outlook 2010 or Outlook 2007 on a computer that has Outlook 2003 installed, you may receive the following error message when you try to start Outlook 2003:

Cannot start Microsoft Office Outlook. MAPI32.DLL is corrupt or the wrong version. This could have been caused by installing other messaging software. Please reinstall Outlook.