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 AdwCleaner to make sure that there are no leftover rogue registry keys or toolbars in your system.
AdwCleaner will offer the possibility of force-removing the plug-ins automatically. Leave them unchecked in the browser section, when they're displayed and that's it. Reboot the PC and the plug-ins will be removed.