No. You should uninstall the new version of EmEditor before installing an older version of EmEditor. Failure to do so might cause some new DLL files to remain in the install directory, which can be incompatible with the older version of EmEditor. Before you uninstall the newer version, you should exit all EmEditor windows including the Tray Icon. When you uninstall the new version, you will be asked to keep all the settings. Selecting YES will keep all the settings that may be used in the older version of EmEditor. If you are asked to restart Windows during the installation, you should restart Windows.