I've already tried CCleaner. I get that same error message when I try to uninstall using CCleaner. Same as when I try to uninstall from Control Panel's Programs and Features. I even tried navigating to the game folder and running unins000.exe, same message every time.
The thing to do with Ccleaner is to manually delete the game folder (highlight it and use the delete key) and then run the registry cleaner part of Ccleaner (scan for issues). Ccleaner will find anything the game left behind in the registry.
And there's also Revo Uninstaller.
If you try uninstalling and reinstalling, make sure your antivirus is disabled while you do it.