Tk is a better option IMHO. It tries for Win32 look and feel but they have done it the hard way ie rebuilt the Windows widget/icon set. There is much discussion about the pros and cons of this but the bottom line is that Tk does not always look as Windows like as you might want.

Esseintially it sounds like you want to pack a folder view widget into your main Window. It can then be rooted on C or whatever but expansions will persist.

I avoid GIUs like the plague as they can consume endless hours with tinkering to get the tabs to behave like you want, the buttons to look just so, etc, etc. I spend most of my time on the Linux command line now.