You can't install two products of different versions together if both products use Click-to-Run as the installation technology and those products have overlapping Office applications.You can't install two products together that have the same version but use different installation technologies.What governs whether an installation scenario is supported are these two rules: The two main things that determine whether Office, Project, and Visio can be installed together on the same computer are the version of the product and the installation technology used to install the product. But, there are some combinations of Office, Project, and Visio that can't be installed together on the same computer. In many cases, you can install Office, Project, and Visio on the same computer. Supported scenarios for installing different versions of Office, Project, and Visio on the same computer
