You want to
violate commonly expected UI style, and very brutally. The only help you can get is: stop wanting it. How to stop it? There are different techniques: yoga, meditation… :-)
Anyone can easily maximize any Window using standard method. All users expect it. If your form layout can assume different sizes but is only usable at maximum size, it means that the UI design is all broken. The design should be size-tolerant, which is not too hard to achieve. You should not use this wrong UI conception.
You will find some detail in my past solutions:
Zom Out malfunctions when Screen resolution changes[
^],
GUI Apperance - C#.Net[
^],
a simple code sample:
how to dock button so that it can adjust with the form[
^].
—SA