So i recently got myself into a sticky situation, it seems like windows 'forgot' about a program I had installed (some drives changed letters / not really sure what happened).. I could find files that it created, but in 'Programs' and 'Add/Remove Programs' it is not there.
Also, when I use the 'programs' installer, it says it cant install because it exists already (to some extent), and I can un-install because windows doesn't know it exists.
BUT! I have an executable of the 'program' that works.
So I am wondering what the difference is between an executable, and what windows considers to be, and keeps track of, a 'program'.
This is definitely the kind of program that would show up in 'add/remove programs', as I have several other very similar ones from the same company that show up there, and I know it used to show up there.
I am not looking for wikipedia answers, I am interested in what exactly a 'program' is. What are the necessary pieces that make up a 'program' as far as windows is concerned?
For a program to show up in "add/remove programs", it needs to be installed. Typically, this is done through an installer that takes care of registering the program with windows and modifies the environment so that the program functions properly. It may modify the registry to store user preferences for example...
When you have just an executable, it's not necessarily installed. It may be standalone. Some programs don't absolutely need to be installed even if it's the canonical way to add a program in the Windows system. That's why it may work. Another executable may fail because it relies on modifying the state of the system to work properly.
I hope it helps :)