The quickest and easiest way to resolve this issue is to reinstall the entire application. Therefore, first of all you need to remove your installed CCleaner (Control Panel > Uninstall a program). After that you will need to download CCleaner again, but this time download the latest version. You can download it through the Software Informer application's page, or you can download it directly from its official webpage. After the download is complete, open the setup files and start the installation again.