First click "Start", in the Empty box, enter "Regedit" (excluding the outside quotation marks) such as figure (also can win key +r, pop-up running program and then enter "Regedit"); Click OK to open Registry Editor
And then navigate to the "Hkey_local_machine/software/microsoft/windows/currentversion/authentication/logonui/background" branch; You will find a double byte value named "Oembackground" (if not, you can create one yourself), and finally right-click the Double-byte value, select Modify, and modify its value to 1. Change the value of the Oembackground, if 0 means that only the Windows default background is used without an OEM background, and if 1 is an OEM background
The next step is to use the wallpaper of your choice instead of the default one, first find the directory of the lock screen wallpaper, it is here: c:windowssystem32oobeinfobackgrounds; The Infobackgrounds directory does not exist by default, We need to create these two folders ourselves, and then put our favorite lock screen wallpaper here: c:windowssystem32oobeinfobackgrounds
Name your favorite lock screen wallpaper as backgrounddefault.jpg (note that JPG is a file format, not a filename), and put it in the path described in step 3rd.
5 Do not need to restart the computer, with
Win+l
Test the results of the setup.