Just the facts, Ma’am!
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background]
“OEMBackground”=dword:00000001
C:\Windows\System32\oobe\Info\backgrounds\backgroundDefault.jpg
That’s it! No 400 word essay necessary to explain this.
To help with the Registry entry – zipped .reg file to enable login background image.

do you change the oembackground dword to string to enter the path or do you create a new key?
equally or more important… how to change the login sound in Windows 7 Starter (all my little notebooks have that problem)..
thnkx for posting..
The key added to the registry only allows OEM background images. When one is allowed it must then have the exact path (including name) as given in the post.
No idea about startup sounds – sooory!