According to this blog entry by Raymond Chen, Windows NT "minimized" windows by moving them to the coordinates (-32000, -32000), and, in the context of the sentence where that is stated, it implies that this was the case in the early versions of Windows NT (3.x, 4...).

In modern versions of Windows NT (such as 7, 8, and 10), is this still the case?

Is there a program that one could write to demonstrate the presence/absence of this feature on a modern Windows OS?