Don't worry, regardless of what anyone tries to say, choice of engine is never an obvious one.
Without some coding experience, making a game is always going to pose... difficulties.
That said, your best bet is probably either GameMaker or Stencyl. I'd recommend GameMaker as a better start-point (perhaps because it was actually designed to be an entry-point to game development)
If you were making a genre-typical 2D platformer, you could make the whole thing with just GM's drag and drop functionality.
However, your idea is an atypical genre, so you'll need to work around that in some way. For icons that you can click, windows that appear/disappear, and the general progression of the game (e.g. user opened 'file.exe' on the desktop, so a new file 'ReadMe.txt' appears on the desktop), then you can probably do that with just drag and drop features.
I should probably elaborate on drag and drop. Basically, you create objects (like an icon) and place them in the scene (the game world). You can then set an object's behaviour and conditions for that behaviour. For example, move an object around the screen if it's clicked on.
Anyway you slice it, you'll want to understand variables and the basic structure of a game. GM does a fairly good job of easing you into it.
For anything more complicated than simple user input however, and you're going to need to delve into GML (Gamemaker's scripting language).
For instance, if you wanted a text box to take in player input, and then wanted to interpret that input as something (e.g. the user enters 'hello', you might want to write 'hello' in response. Or if the user enters 'hello Yolanda', you might want to write 'my name isn't Yolanda' in response). You'd need to get stuck into the code for sure.
And of course, Unity is always a decent engine if you're unsure. Not particularly great at any one thing, but it's probably the most versatile one out there. Highly recommend playing with it and C# if GameMaker feels too restrictive for you
EDIT: I've made the assumption that you don't have any (or much) coding experience. Please shoot me down if I'm wrong :)