I suspect that for Windows 10 the window appearing but not fully drawn is a function of the introduction of a display compositor (Desktop Window Manager) in Win

I suspect that for Windows 10 the window appearing but not fully drawn is a function of the introduction of a display compositor (Desktop Window Manager) in Windows Vista - this is also what solved the famous issue of Windows "leaving trails" of application Windows when they were unresponsive, and also permitted all the "aero" effects that Vista and 7 used as selling points. Windows XP and earlier used a Stacking Window Manager.