I think your just getting started and you are a bit confused about what a game engine is - you seem a little bit overconfident in your knowledge which judging by your posts is not very extensive at this point.. no offense just that's what I collect after reading everyone's replies and your replies...

you might just try and step back a bit and think about what is a game engine and why do you want to make one? why not start with a simple game if your wanting to learn - because if your goal in making a game engine at this point is anything other than learning its probably a bad idea...

VC++ or VS or Qt or whatever IDE isn't your limiting factor at all right now - you can make GUI's or game engines or whatever you want in any of these pretty much with a minimal change in effort - its really just whatever flow makes you happy. Qt creator - the thing that lets you make widgets in a graphical environment creates "*.ui" files that can be used in any of these IDEs.

Are you really interested in using these GUI builders to create your own ingame menus?

If so, I strongly suggest you have a look at the export format and decide which will be easiest to parse. Qt uses (or used) QML (very similar to XML), which might not be so tricky. If I recall, the Winforms designer in Visual Studio is missing when using the C++ language since version 2005. Even so, it generates commented code rather than a parsable document.
The newer Windows 8 store GUI system uses XAML which again is quite similar to XML so might be an OK choice.

Other examples which I have actually written parsers for in the past is the xml generated by Glade (standalone Gtk+ GUI builder) and Borland C++ Builder which is also pretty straight forward.

Are you really interested in using these GUI builders to create your own ingame menus?

If so, I strongly suggest you have a look at the export format and decide which will be easiest to parse. Qt uses (or used) QML (very similar to XML), which might not be so tricky. If I recall, the Winforms designer in Visual Studio is missing when using the C++ language since version 2005. Even so, it generates commented code rather than a parsable document.
The newer Windows 8 store GUI system uses XAML which again is quite similar to XML so might be an OK choice.

Other examples which I have actually written parsers for in the past is the xml generated by Glade (standalone Gtk+ GUI builder) and Borland C++ Builder which is also pretty straight forward.

Since qt (creator, designer etc.) is like visual studio, I'm going to use it to create a game engine (not anytime soon). Qt seems more "designerish" than visual studio and at least i know it'll do what i want.

Qt uses (or used) QML (very similar to XML), which might not be so tricky.

No, not really. QML is very similar to JavaScript mixed with JSON. XML doesn't really come in anywhere. That said, I would consider it completely unrealistic to use QML without the actual Qt backend. The amount of code you would have to implement to get even a simple sample working and rendering would be nightmarish and would also include reimplementing something like Qt's meta object system.

My next thread will determine if qt is for me. If you use use qt, please answer the thread.

Thanks a lot.