I am trying to overlay a fullscreen application on Windows 10 using C++ (I’d like to be able to render styled html later but just making the overlay work now is fine); however, I am running into a few issues with the approaches I have tried: Since the game must be in fullscreen mode, creating a transparent window and setting it to topmost is not viable. Additionally, the game has anticheat, so I do not want to inject any code or modify its memory if possible.