Which technology stack do you recommend for developing native windows executable (has GUI), other than .NET stack?
Other that C++ (MFC, ...) some could be named; yet which one is mature and pragmatic enough?
Python is a good choice for some sorts of problems, and you can package python programs into a single .exe using py2exe.
Here is a nice py2exe tutorial: http://www.py2exe.org/index.cgi/Tutorial
Tcl/Tk is very mature, has a small footprint, is easy to learn and use, and uses native widgets on Windows and the Mac. Plus, it has a deployment mechanism second to none by way of starpacks, starkits and tclkits. You can either create a single-file executable (starpack) that embeds a very full featured virtual filesystem, or a two-file solution of a platform-specific runtime engine (tclkit) with a platform-independent application file (starkit).
It's downside is that it's low on "flash" -- there's not a lot of support for transparency, multimedia, animation and fancy graphics. So, depending on whether or not you need a lot of eye candy it may or may not be the right choice for you.
For native Win32 GUI apps, I've found nothing that beats Delphi. (Your question asks about Delphi 7, but please note that all versions of Delphi (including the latest - Delphi 2010) can produce single, standalone .EXEs).