Personally, when making a gui in C++, I use
Juce. It may have been designed for another purpose, but I have yet to see an easier way for making gui's.

Definitally does not look like an standard OS gui though, it is very much its own style...
EDIT: It works, somewhat, not sure if it is my corruptish .NET install or what, but may as well mention them to make sure it is either me or whatever. The fact that it runs at all is interesting since most things don't.
If I click a menu item, like File, so it pops-up, and move the mouse over to edit, the pop-up disappears, but edit's pop-up does not appear, it just seems to all reset. If I open a file like test.nut, the text editor acts *really* odd. None of the shortcuts work (can't do things like ctrl+z to undo). Right-clicking does not work (no popup menu for edit/paste/etc...). In the options box, things like the layout are not pre-selected based on what the current value is.
Honestly, I'm not sure how the .NET forms work in full, but MFC and wxWidgets and so forth, all the listed things are standard things that you have to actually work at to disable to get to how they act in this mannor. Things like preventing the right-click in the text editor you would have to override the contextEvent on that object and return false to not have it do anything (or pop-up your own or what-not).
I'm not sure I see the point of "Exit Config" since there is an X box. If anything, and Ok, Apply, and Cancel would be best as changing the options as they are clicked is not always wanted, sometimes things are misclicked and so forth.
When many tabs are open, the little scrolling arrows should scroll the display while it is held (as it does in VS) instead of having to click it multiple times.
The File->Recent also does not work (that is also built into MFC and so forth, I don't even know how to disable that in MFC without removing the whole Menu entry...)