When you run the BlueZone Web-to-Host 7.1 Wizard installer on a machine that has an older Wizard installed, such as version 5.2, you are not actually upgrading the existing Wizard. You are installing the new version 7.1 Wizard alongside of your existing Wizard. This process is called a side-by-side installation. This means that you can run both Wizards on the same machine, making it easier to migrate your existing Sites to the new version.