After you use the Microsoft Office Customization Tool (OCT) to add an additional installation point to a 2007 Microsoft Office suite installation, you cannot locate the registry entry. The additional installation point does not appear as a Microsoft Windows Installer source for a 2007 Office product in the registry under the following registry key:
This issue occurs because the 2007 Office suites use an additional installation point only to maintain the integrity of the files that are cached in the Local Installation Source (LIS) in the MSOCache folder. Because the installation is launched from the MSOCache folder after the cache has been built, the LIS is the location that is registered by Windows Installer.
This behavior is by design.
When you use the OCT to add an additional installation point to the 2007 Office suite, the registry information is located under one or more subkeys of the following registry key: