You can use this picture as a loginscreen for Windows.
If you want to set a picture as a background for the Login Mask, do this: (Windows 7 AND Windows Vista i think)
1. Press the Windows-Button and "R" and type "regedit"
2. Search for the following String
3. On the right side are lot of Strings choose
"OEMBackground", double click and set the number from
"0" to "1" and press OK
4. Go to "C://WINDOWS/system32/oobe" and create a new
folder called "Info" inside this folder, you create another
folder called "backgrounds"
5. Rename the Picture to "backgroundDefault" and copy it to
the folder, you just created.
THIS WORKS WITH ANY OTHER .jpg PICTURE BUT IT HAS TO BE SMALLER THAN 256kb !!
Maybe you can give me some feedback if it worked?