If you have an old version of CCleaner (version 5.45 or earlier) then it is not compatible with recent versions of Windows 10. Please download the latest version of CCleaner from https://www.ccleaner.com.
You may also experience difficulties installing even newer versions of CCleaner if you have set Windows 10 to only permit software purchased from the Windows Store. If you get a message when you try to install CCleaner that says "The app you're trying to install isn't a verified app from the Store" or "You can only install apps from Microsoft Store" then you may need to make some changes to your Windows settings to permit you to install software like CCleaner that you have bought or downloaded for free from elsewhere.
You can do this by going to Setting > Apps > Apps & Features in Windows and then for the "Installing Apps" option, change your setting from "Allow apps from the Store only" to either "Warn me before installing apps from outside the Store" or "Allow apps from anywhere", if you would prefer not to be asked for permission each time.
If your setting is "Warn me before installing apps from outside the Store" then you will see this message "The app you're trying to install isn't a verified app from the Store". You can just click "Install Anyway" to continue.