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.
Revo will take care to uninstall the program and leave no traces behind and AdwCleaner will remove other hidden entries or services that might run in the background to reinstall the program.