Always use custom logon background
Supported on: Windows Server 2008 R2 and Windows 7
Registry
HKLM
Software\Policies\Microsoft\Windows\System Value name: UseOEMBackground
Enabled: UseOEMBackground = 1
Disabled: UseOEMBackground = 0
Description
This policy setting ignores Windows Logon Background. This policy setting may be used to make Windows give preference to a custom logon background. If you enable this policy setting, the logon screen always attempts to load a custom background instead of the Windows-branded logon background. If you disable or do not configure this policy setting, Windows uses the default Windows logon background or custom background.