Installing multiple EPiServer CMS / Community Editions on the same server
The EPiServer CMS / Community installation packages that you download from EPiServer World are made up of a bootstrapper application (setup.exe) and a few Windows Installer (MSI) files.
One of these files, EPiServerShared.msi, is configured so that only one instance of it may be installed on a computer at the same time. Whereas all of the other MSI’s are configured for “side by side” installation.
What this means is that when EPiServerShared.msi is launched by the bootstrapper application is will check to see of there is already an existing version of it installed on the computer.
If an older version is installed then Windows Installer will replace it with the current one.
However, the problems comes when the version of EPiServerShared already installed is newer than the current one. Then you will receive an error message saying this (if you’re lucky) or if your unlucky some obscure message about a service already running. This is all correct and by design but doesn’t help you get the version of CMS or Community that you want on to the computer.
In these cases, don’t run the setup.exe bootstrapper application but instead run the individual MSI files for the relevant product, such as EPiServerCMS.msi for example.