Changing the Windows 7 Logon Screen image

There are numerous ways to change the background of the Logon Screen in Windows 7. All possible methods, including the steps, can be found in the tutorial below:

How to Change the Windows 7 Log On Screen Background

From the tutorial in the link above, the easiest way IMHO is to use Julien Manici's Windows 7 Logon Background Changer. The application's title speak for itself - it does exactly what it says it does - and it is really simple and hassle-free. And to top it off, it is FREE!!!