If you cannot place a window partially off screen
I like sometimes to drag and drop a window partially off screen in order to view information I need to monitor, such as a conversion’s progress, while working with other open windows. Yet Windows 10 (and sometimes Windows 7) won’t let me do this; it immediately brings such windows back to full view!
At the Easy Access Center in the Control Panel > “Make the Mouse Easier to Use”, I checked the option “Prevent windows from being automatically arranged…”, yet even this did not let me enjoy partial placement of open windows off screen.
Here is a solution I’ve found accidentally. If you Ctrl+Drag, or Shift+Drag a window and drop it partially or completely off screen, it will stay there!
Note that this works only for the left, bottom and right sides. If you want to place a windows off-screen at the top side, get the (free) Window Manipulator.