I'm looking to put an application window behind all other windows. I was thinking of using .NET 4 and WPF or Silverlight.
I don't have any specific drawing code, I just want my application window as my desktop wallpaper while retaining the interactivity (no mucking around with screenshots etc).
Is this even possible and if so, how?
Edit: I'm using Windows 7 x64.
Edit 2: I know the desktop is drawn to a window with id 0 (or something like that). Can't I use interop calls to put my window as a child of window 0?