Answer
Most ArcGIS software requires a complete uninstall of the previous version before upgrading to a newer version. However, this requirement is different for CityEngine. CityEngine utilizes unique destination folder locations established for each install, therefore it is possible to have multiple versions of CityEngine installed on the same machine.
Note:
It is usually best to stick with a single version; however, in some cases there may be a necessity to use a different version for a particular task.
For a multi-version install of CityEngine to work properly, it is important to note a few details when going through the installation process.
• Notice the destination folder defaults to C:\Program Files\Esri\CityEngine during the install setup.
![[O-Image] CityEngine Default Location](https://webapps-cdn.esri.com/CDN/support-site/technical-articles-images/000011680/00N39000003LL2C-0EM39000000wdNV.png)
• Change the destination folder to a unique location for each installation. Making unique folder names for each installation allows the new version of CityEngine to be installed while continuing to maintain the existing version on the system. As a best practice, use the version number of CityEngine to name the folder; this aids in keeping the installations organized.
![[O-Image] CityEngine folder naming convention](https://webapps-cdn.esri.com/CDN/support-site/technical-articles-images/000011680/00N39000003LL2C-0EM39000000wdNX.png)
Warning:
If the default installation location is not changed, the new software overwrites any existing installations in that directory. Shortcuts and Start menu icons then reference the newer version.