Thanks for your reply.
So in App & Features when I click on Uninstall, I have the notification "would you like CCleaner Browser Installer to make modification" blabla. I click Yes and nothing happens. Nothing at all No window appearing. I tried also to find the uninstaller file manually in the explorer: still nothing happens when I click on "setup.exe" in the "installer" folder.
I'm sorry I don't remember how precisely I installed it, I don't have the installer. I guess it was with CCleaner itself, not sure...
Let me know if you need more information!