Short improvised discussion:

Jim : Hello Candide. How do you install a new programs on your Windows?
Candide : Hello Jim. How do I install a program? but it's simple: I run the setup program, I kindly click where I am asked to do it, and that's all. It's really a stupid question!
Jim : Oh yes, really? and how do you do when you want to uninstall this software that was so easy to install?
Candide : For that, I double-click on "Add / Remove programs" of the control panel, I search for it in the list, and I click on the "Remove" or "Delete" button. It's really simplicity itself. You did not know that?
Jim : Being like your father in this wonderful world of computers, I know everything you know yourself! But, tell me, if your program is not in this list, what are you doing?
Candide : It is impossible, of course!
Jim : It's impossible, so it happens, according to Murphy's laws.
Candide : And so, in this case, what have I to do? ...
Jim : You do as I will explain later. I suggest you wait, and to read the explanations that I will detail for the pleasure of seeing you open your beautiful eyes ...

Indeed, the list of installed programs is not always complete, because a software can work very well without being there. But that's not the only problem with the installation of a program. Most of the time, even when you uninstall a software through the control panel, Windows does not return to a state prior to installation. It would be too good. There are still traces of the program: files or registry keys have not been deleted. So much so that sometimes it can not be reinstalled, if the installation decides, after finding traces, that the program is already present, and that it can not be installed twice.

In fact, what's wrong is Windows. Ideally, the state of the computer should be stored prior to installation, then a new program should be installed, and then the system state should be compared before and after installation, to be able to return as much as possible to the initial state when uninstalling the program. Windows is unable to do that. Each program designer must manage the uninstall himself. This is where the problem lies, because the uninstallation is often overlooked by software developers.

The solution I propose here is to use a program that will do all this: it stores the state of the system as it is before installation, then, after this one, it saves all the modifications made to the disks (files and folders created, modified or erased) and to the register. The moment of the uninstall come, it is able to return to the initial state, with the only problem that it can not recreate lost or modified files.

This program is called Total Uninstall. It has become pay, so I suggest you download version 2.35, which is free, powerful, and seems even more interesting than the current versions.
Total Uninstall 2.35 does not install, like all well-written software: copy it where we want and run it.

Download TotalUninstal 2.35.