Windows 7 now supports the ability to load images into the background of the login screen without the use of third-party software or manual hacks.
Although this functionality was designed for OEMs in mind, it is pretty easy to turn on and off using regedit and some images lying around your hard drive.
First, a check is made to determine if the customization functionality is enabled or not. More precisely, a DWORD value named OEMBackground in the
HKLM\Software\Microsoft\Windows\CurrentVersion\Aut hentication\LogonUI\Background key is checked. Its data, of Boolean type, defines whether or not this behavior is turned on, i.e.
1 for enabled, 0 for disabled. This value may not exist by default, depending on your system.
As this is an OEM feature images are derived from
%windir%\system32\oobe\info\backgrounds. Like the registry value, this folder may not exist by default.
Source :
WithinWindows.