Well, to get it to update, you need to grab the desktop image repeatedly in your code, instead of just loading once. So like:
While Not KeyDown(1) SetBuffer DesktopBuffer() Global imagebackground=CreateImage( 773,600 ) GrabImage imagebackground,GraphicsWidth()/2-386,GraphicsHeight()/2-300 windowx = (GraphicsWidth()/2-(773/2)) windowy = (GraphicsHeight()/2-(600/2)) window = CreateWindow ("Game",windowx,windowy,773,600,Desktop(),0) canvas = CreateCanvas (0, 0, ClientWidth (window), ClientHeight (window), window) SetGadgetLayout canvas, 1, 1, 1, 1 SetBuffer CanvasBuffer (canvas) DrawBlock imagebackground,0,0 FlipCanvas (canvas) WendThe only thing is that this will cause moderate to major slowdown on most PCs. To combat this problem, try creating some code that only updates the background if the window is moved.