You don't have to uninstall a previous version before installing a new one.
If you want to keep all settings of a previous version (like customized excluded registry entries, excluded drives, paths to search for matches), then you should not uninstall old version before installing the new.
If you want to use both old and new versions, you can install new version into another new folder. Otherwise you can install the new version into the same folder where the old version is. Then the installation will upgrade all old program files and keep all backup files.