You can customize the background image of the logon page in the Windows 7 as per your requirement.
The default image is set as background on the logon page in Windows 7. To change background image, perform the following steps:
Launch regedit in the command prompt.and specify
The(UAC) prompt is displayed.
Clickto navigate to the directory.
NOTE:The Background directory is located in Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI directory.
Set OEMBackground entry to 1.
NOTE:If the OEMBackground entry does not exist then create an entry with the type and set value to 1.
Navigate to C:\Windows\System32\Oobe directory and create a directory as info.
Create a directory as backgrounds in the info.
Insert the preferred background image in backgrounds directory and rename the image as backgrounddefault.jpg.
Launch GPEDIT.MSC in the command prompt.and specify
The Lprompt is displayed.
Navigate to Local Computer Policy\Administrative Templates\System\Logon directory.