For a long time Windows users have been using third-party tools and hacks to customize the Windows Logon UI, but Microsoft has finally realized that and have made this option available on Windows 7.
In the latest build 7057 of Windows 7, Rafael Rivera found out that now you can customize the logon UI without any hacks or patches. You will still have to do it manually, but it will be safe as no patching of system files will be involved.
How To Change Windows Logon UI Background
First, you need to go to the registry, and enable the option from there. Navigate to the following path:
HKLM\Software\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background
Look for the DWORD value type called ‘OEMBackground‘ and change its value to 1 (default value should be 0, which means to disable it).
Then navigate to the following folder %windir%\system32\oobe\info\backgrounds and put your wallpaper in this folder. Remember, this folder might not be there because the registry and this folder is for OEM versions of Windows 7 only. So you will have to create it yourself. Wallpapers should be in less than 256 KB in size and in JPG format. Replace/add images with the following nanmes:
backgroundDefault.jpg
background768×1280.jpg (0.6)
background900×1440.jpg (0.625)
background960×1280.jpg (0.75)
background1024×1280.jpg (0.8)
background1280×1024.jpg (1.25)
background1024×768.jpg (1.33-)
background1280×960.jpg (1.33-)
background1600×1200.jpg (1.33-)
background1440×900.jpg (1.6)
background1920×1200.jpg (1.6)
background1280×768.jpg (1.66-)
background1360×768.jpg (1.770833-)
Windows automatically detects the background from backgroundDefault.jpg file. If the background is smaller in resolution, it will be stretched to fit your screen. Or if it’s too big in size, then the default Windows 7 logon backgrounmd will load.
