Configure the login and Welcome Screen in Win7
Windows 7 no longer supports the classic logon screen, that is available in WinXP. Windows 7 provides a welcome screen, where one can select between the available user accounts.
Windows Vista already provided several options to configure the logon screen, and Windows 7 adds some extra on top.
Change logon screen background
Save the custom background image as backgroundDefault.jpg in the following folder (Must be less than 256 KByte in size):
Then activate loading of OEM background image with this DWORD registry key:
[HKEY_LOCAL_MACHINE \Software \Microsoft \Windows \CurrentVersion \Authentication \LogonUI \Background]
OEMBackground = 1