If you want to properly uninstall this application, I recommend you to go to Control Panel > Uninstall a program > search there QuickTime > right click on it > and select uninstall. Follow the steps and in only a few moments you will get rid of this application. Moreover, there is another solution to remove QuickTime from your computer. Go to Software Informer application's database, search there for an uninstalling tool. Furthermore, this tool can be used for all programs that you want to remove from your computer.