A Registry tweak

The process begins with a very minor Registry tweak.When the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background key opens, locate and double-click the OEMBackground value. When you see the Edit DWORD dialog box, change the value data from 0 to 1, as shown in Figure C. (If the OEMBackground value doesn’t exist in the Background key, you’ll need to pull down the Edit menu from that key and select New | DWORD (32-bit) Value).

Creating folders

In the second part of the operation, you’ll need to create a couple of folders. To begin, launch Windows Explorer. Then navigate to the %windir%\System32\oobe\info\backgrounds folder. You may need to create the info and backgrounds folders.

Configuring the wallpaper

You can use any image that you want for your new Logon screen wallpaper. However, the image has to be in JPG format and you need to name it backgroundDefault.jpg. When you copy your file to the Windows\System32\Oobe\info\backgrounds folder, you’ll encounter and will need to work through a confirmation dialog box similar to the one shown in Figure D.
Two other things to keep in mind: First, the actual file size of backgroundDefault.jpg cannot exceed 256 KB. Second, you’ll want to use an image whose dimensions match the screen resolution that you are using. If you use a file whose dimensions are smaller, the image will be stretched and may appear distorted.

Images Name with resolutions

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-)

Please NOTE: Images must be less than 256kb in size

The backgroundDefault.jpg image is loaded and stretched-to-fit when a resolution/ratio specific background cannot be found.

Altering shadows

As you know, the button and the text used to identify your user account on the Logon screen have shadows behind them to give them a 3D-like look, and these shadows work well with the default Logon screen wallpaper. Depending on what image you use for your new Logon screen wallpaper, these shadows might not work so well.

In addition to making it easy to change the Logon screen wallpaper, Microsoft also made it easy to adjust or disable the text and button shadows to accommodate your particular image.

To alter the shadows, launch the Registry Editor again as described above and access the

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI folder

Once you open the LogonUI folder, you’ll create a new DWORD value called ButtonSet, as shown in Figure E. You can then configure the shadow by setting the value data to one of the following numbers:

• 0 — Light shadow
• 1 — Dark shadow
• 2 — No shadow

via Change and customize Windows 7’s Logon screen wallpaper | TechRepublic.