How to Change the Logon Screen on Windows 7

Step 1: Open the Windows Start menu and enter regedit into the search bar.  Step 2: Right click on HKEY_LOCAL_MACHINE and select Fi...

Step 1: Open the Windows Start menu and enter regedit into the search bar. 

Step 2: Right click on HKEY_LOCAL_MACHINE and select Find. 

Step 3: Search for OEMBackground, which should be in:

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft
\Windows\CurrentVersion\Authentication\Logon\UI\Background

If the key does not exist, add a new DWORD value with the name OEMBackground.

Step 4: Double click on the entry OEMBackground, and change the value from 0 to 1. 

Step 5: Open Windows Explorer and go to the following path: C:\Windows\System32\oobe

Step 6: Create a new folder named info, and open it. 

Step 7: Create a new folder within info named backgrounds. 

Step 8: Rename your desired wallpaper as backgroundDefault.jpg and place it inside the folder backgrounds (images must be less than 245KB in size).

That should do the trick, now just lock your PC, log off or reboot and enjoy.