No support for multiple Office versions installed on a machine with Remote Desktop Service (RDS)
On a computer with Remote Desktop Service (RDS) enabled, it is possible to install multiple versions of Office. However, this is not a supported Office configuration.
To get the computer into a supported configuration, you can either disable RDS or you can uninstall versions of Office, leaving only one version installed.
Please see the following articles for additional information about recommended and supported methods for installing multiple versions of Office on the same computer: