Till Windows Vista & Xp there was no support for changing Login Screen background and you have to use third party apps like logon studio for changing login screen background. However in Windows 7 Microsoft has done good job by allowing users to change Windows 7 Logon Screen without need of third party apps.
We have already revived Logon changer & LogonUI Changer for Windows 7. Here is another cool utility Windows 7 Logon Screen Rotator developed by one of Neowin forum member which lets you to rotate Windows 7 Logon background screen randomly.
You can select upto 10 images and Logon Screen Rotator will automatically rotate your Windows 7 logon screen.
Screenshot of Windows 7 Logon Screen Rotator
To use the application run the exe and choose your images, then click “Enable Settings and Exit” & specify set of images you want to rotate through on Windows 7 Logon Screen.(via)
Download Windows 7 Logon Screen Rotator
http://www.mediafire.com/?sglkccox0ss
