In other words, the programs you remove are never completely removed. We always need an uninstall manager to remove leftover files. Normally, when you remove any program from your computer, it is likely to leave residual files behind. It would not be correct to think of this situation only as a file. Input outputs are recorded in the registry. Iobit Uninstaller 13 PRO Key is the most comprehensive uninstaller I have ever seen. It is one of the rare programs that must be installed after the format. It is known as a program uninstaller.