You can uninstall this software by going to Start -> Control Panel -> Add/Remove Programs (for Windows XP) or Programs and Features (for Windows 7), select the program and hit Uninstall. If this method is not working, you can try using a third-party tool in order to force it to uninstall by wiping out all traces of its presence from the system. To do that you can use Revo Uninstaller. Also, you can use AdwCleaner to make sure that there are no leftover rogue registry keys or toolbars in your system.