I'm trying to remove the title bar from an external app. The reason is I don't want anyone to be able to move it.

But my code below doesn't remove the title bar. Could this be because it's not removable? I read somewhere title bars of external apps may be not removable if the app doesn't allow it.

So, I'm not sure why my code doesn't work - either it's wrong or the app doesn't permit it?

int style = GetWindowLong(app1Win, GWL_STYLE);
style = style & ~WS_BORDER;
SetWindowLong(app1Win, GWL_STYLE, style);
SetWindowPos(app1Win, HWND_TOP, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);

Try adding WS_POPUP to style.