After installing a newer version of the program, the HICSOAP shortcut on the Desktop defaults to running the newly installed version. But you can still run the previously installed versions. When you install a newer version, the previous versions are not removed. Here's how to create a shortcut on the desktop to a previous version. In this example, there are two versions installed 2016.0621a and 2016.0819. If you want to run a version that is not installed then you need to download it and install it. This video only covers the case of running a version that is already installed.
Please keep in mind that although it's rare occasionally new versions of the software does modify the basic structure of the database. So it's not always possible to open a database with an older version.