DesktopWindow.HasMinimizeButton
From Xojo Documentation
Read-Only Property (As Boolean )
BooleanValue = aDesktopWindow.HasMinimizeButton
New in 2021r3
Supported for all project types and targets.
New in 2021r3
Supported for all project types and targets.
If True, the window has a Minimize button in its Title bar. The default is True.
Notes
You can only change this setting while in the Window Layout Editor.