This used to work until I re-installed Windows7.
I have written a Python program, run at startup, to change the desktop background depending on the time of day.
Since the re-install it works with an Aero Theme, you see the desktop Aero picture instantaneously until the program takes over. My backgrounds are all plain colours.
If you personalise the desktop and make it a Plain background the program cannot overwrite it until logoff when you see my colour instantaneously.
Where should I look for a difference in MS plain desktop, this installation from my previous one?