We've had some questions about the Windows Installer version required by the Office 2010 Office Customization Tool (OCT) and would like to clarify the requirements.

In Office 2010, there are two architecture-specific versions of the OCT, one for 32-bit Office 2010 and one for 64-bit Office 2010. The 64-bit version of the OCT supports 64-bit client editions of Office 2010, and provides the same user interface, capabilities, and configurable settings as the 32-bit version. The OCT files are located in the Admin folder under the x86 (32-bit) and x64 (64-bit) folders, respectively.

The Office 2010 release requires Windows Installer 4.0 on computers that are running the 64-bit version of the OCT or importing 64-bit Setup customization .msp files. Windows Installer 3.1 does not recognize properties such as “ProgramFiles64Folder,” which are used by the 64-bit version of the OCT and the OCT Import feature. Windows Installer 4.0 was released with Windows Vista, Windows Vista  with SP1, and Windows Server 2008.

For information about Windows Installer, see Windows Installer (http://go.microsoft.com/fwlink/?LinkID=111108), and Released versions of Windows Installer (http://go.microsoft.com/fwlink/?LinkID=201918).

 For information about the OCT, see Office Customization Tool in Office 2010 (http://technet.microsoft.com/en-us/library/cc179097.aspx). For information about the Import feature, see Import an Office 2010 Setup customization file (http://technet.microsoft.com/en-us/library/ee681791.aspx).