Honored Contributor
Honored Contributora newer version soes not install over an existing version like a service pack does.
so you need to install the newer version, but it is up to you if you uninstall the previous version. it sometimes helps to keep to oleder versions installed f.e. if parts of your project are based on ip funtionality from an older version that might has been changed in the new version. FIR for example had paths releated to the installation. if you upgrade your quartus and uninstall the previous verion, the you had to upgrade your FIR parts too. 18x18 multiplier are created with 9x9 multipliers if only 9x9 is available