Windows 7 Logon Background Changer

From Julien MANICI:

Windows 7 Logon Background Changer is a free open source software that lets you change the wallpaper of the Windows 7 login screen (also known as "welcome screen" or "login screen"). It does not change any system file, and the program itself does not requires admin rights to run (it will just ask you to run as admin a very simple cmd file that creates the required folder and registry key with the appropriate rights) It creates a few JPEG files based on the image you want to put as wallpaper for the Windows 7 login screen, applies the appropriate cropping and sizing and saves them using the best compression quality possible.