Whenever you uninstall a program, it's not hard to find parts of it still floating around somewhere along on your system. This happens due to fragmentation of said program, which can use several folders. As an example, some programs will use both folders in Program Files and in AppData\Roaming.

There are a few programs that will take care of these pieces of programs left after an uninstallation. One of these programs, for example, is IObit Uninstaller.