My personal opinion on Windows 10 The default login background image is quite unaccustomed，Maybe it’s a bit tired after watching for a long time，Previously, there was a way to modify the web crawler，But no relevant teaching was found。Search for foreign articles today，Finally found some information。
may be based on safety considerations，Microsoft did not make the login background image like a wallpaper so that users can easily modify it，Even after finding the relevant directory，No permission to access，I guess it might be because they are afraid of hackers implanting malicious programs into the image files.，Let windows 10 Without logging in yet，Malicious behavior。So if you want to modify this picture，Need to be aware of the relevant risks in advance。
◎ Find the "SystemData" folder in the following path，Modify the owner of the directory to the current account，To access。
C:\ProgramDataMicrosoftWindows
◎ Enter the following path，You can find three pictures with the same resolution，This is the login background image。
C:\ProgramDataMicrosoftWindowsSystemDataS-1-5-18ReadOnlyLockScreen_Z
◎ Copy the new picture to this directory and change it to the default file name。
※ If after restarting，No background pattern，Can check whether the permission of "drawing file" is not available “SYSTEM” Authority，Just fill it up。
【參考連結】
- Force a Corporate Lock Screen to Windows 10 Pro 2004 – Active Directory & GPO – Spiceworks
- [SOLVED] Change Windows 10 lock screen background image (GP)? – Spiceworks – Page 4
