How to modify the win7 lock screen background wallpaper

First click “ start & rdquo;, enter "ldedit" in the empty box (not including the outer quotes) (can also win + R, pop up the program and then enter "Regedit") Then click the “OK” button to open the Registry Editor.
Then navigate to the "HKEY_LOCAL_MACHINE/SOFTWARE/Microsoft/Windows/CurrentVersion/Authentication/LogonUI/Background" branch; you will find a double-byte value called "OEMBackground" (if not, you can Create a new one, and finally right click on the double-byte value, select Modify, and change its value to 1. Change the value of OEMBackground. If it is 0, it means that the OEM background is not used. Only the Windows default background is used. If it is 1, it means the OEM background is used.
The next step is to replace the default one with the wallpaper of your choice. First find the directory where the lock screen wallpaper is placed. It is here: C:WindowsSystem32oobeinfobackgrounds; By default, the infobackgrounds directory does not exist. We need to create this new one. Two folders, then put your favorite lock screen wallpaper here: C:WindowsSystem32oobeinfobackgrounds.
Name your favorite lock screen wallpaper as backgroundDefault.jpg (note that jpg is the file format, not the file name), and put it in the path described in step 3.
5 Do not need to restart the computer, use
Win+L
to test the results of the setup.