Try using Revo Uninstaller. Even if it can't uninstall the application normally, it will force it to uninstall by wiping out all traces of its presence from the system.
After that, try running Combofix to make sure that there are no leftover rogue registry keys or toolbars in your system.
Revo is good for uninstalling applications but in order to remove the registry items completely use another tool called CCleaner. It's a good choice when it comes to safe registry cleaning.