Put the other two suggestions together and use Python with wxPython (python bindings for wxWindows). I would highly recommend python instead of C/C++ becuase you won't have any compilation headaches or overhead while developing or deploying.
You may also want to consider GTK as the gui toolkit. It has fairly complete python bindings. It also has a visual builder (glade) and a library that can create the gui at runtime (libglade) rather than generating static code for it. This is what I am planning on doing for some projects I have in the queue. I don't know yet how well libglade runs on windows, but if it doesn't I might convert it to python :-). -D
