For a project of mine I want to open two fullscreen windows on two different monitors. I use ChangeDisplaySettingsEx() to make each monitor switch to the resolution I need (currently, each monitor is switched to 640x480). Then I want to open a WS\_POPUP window that covers the whole screen on each monitor. To make sure that the window stays up front, I also set the WS\_EX\_TOPMOST flag.

This is all working fine as long as only a single monitor is concerned. Once I try to open a second fullscreen window on the other monitor, my window on the first monitor of course loses its focus and suddenly appears behind other windows which looks really ugly because we're in 640x480 now. This behaviour is of course logical because there can be only one topmost window but how am I supposed to use two fullscreen windows on two different monitors then? I'd somehow need to force *both* windows to stay up front and cover all the other windows behind them. 

Is there a clean way to implement such a thing or is this not possible at all without resorting to hacky not-so-sure-whether-it-will-work-in-newer-or-older-Windows-versions approaches?

Thanks!