I currently recommend the .NET Framework as the easiest way to develop GUI applications for Windows. It's got decent tool support, it's free of charge, it's got a pretty thumping library that covers all the important things you might want (or at least I want to do, so far). I'm not all rah-rah C#-is-the-one-true path, but the alternatives - Java, C++ development with MFC or another class library, Python, whatever - just can't match it in terms of getting Windows stuff done.

You are in a box though. The .NET Framework and its libraries define the boundaries of what you can do, and when you bag up against the edges of the box things can get unpleasant. It's nowhere near as bad as Visual Basic was, when an experienced Windows developer would smash up against hard barriers within about five minutes. The .NET box is much bigger, and you can, if you need to, use things like PInvoke or COM Interop to breach the boundaries. It can be a little hairy-scary, but you can do it. But you are in a box, and you can never quite forget it.

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