You have image shortcut icons on your Desktop and they show a 'thumbnail' of the actual image. You want to change that to show just a generic icon.

I'm not sure you can. Images, (generally files with file extensions .bmp, .jpg, .png, etc), have their icons and shortcut icons rendered into image icons automatically by Windows 7, (and Vista by the way). That is a feature of the two new operating systems.

Mark