Windows 10 – Set Default Lock Screen Wallpaper – Image

Personalization

reg add “HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Personalization” /v “LockScreenImage” /t REG_SZ /d “C:\Windows\BackgroundDefault.jpg” /f

or via CSP

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\PersonalizationCSP]
“LockScreenImageStatus”=dword:00000001
“LockScreenImagePath”=”C:\\Windows\\wallpaper.png”
“LockScreenImageUrl”=”C:\\Windows\\wallpaper.png”