On Windows 10, you have the option to choose Windows Spotlight, a collection of images that will display on the lock screen. However, there’s a flaw with this feature. After selecting the Windows Spotlight option under the Personalization > Lock Screen section of the Settings app, the lock screen from that point on will always display a Windows Spotlight picture upon booting into Windows, that is, should you decide to switch back and use your own picture. When you login to Windows and lock the computer, your selected picture will be displayed like it should. Selecting a different picture will not remove the Windows Spotlight picture upon boot.
There is a way to remove the Windows Spotlight lock screen picture upon boot, but it isn’t as simple as changing a setting. It requires deleting a non-accessible system folder as well as the Windows Spotlight files. There are a few other sites that explain how to do this, but they are for removing a picture that came pre-loaded with Windows 10. Similar to the Spotlight but a slightly different procedure.
WARNING: Use the following at your own risk. I will not be reasonable if this procedure damages your Windows installation.
First, make sure you have your own picture selected for the lock screen, and that the Windows Spotlight option is not selected under Personalization > Lock Screen section of the Settings app.
Next, you need to download a registry file from this site in order to continue. This will add a “Take Ownership” option to the File Explorer’s context menu. This is required as the files and folders that you need to get to are protected and you will be denied access, even if you are logged in as an administrator. (There is also a registry file on that same site that will uninstall the “Take Ownership” option, so you can remove it from the context menu when you’re done).
After you have initialized the registry file, open File Explorer, click on the view tab and make sure the hidden items option is selected. Then navigate to the following folder:
Right-click on the SystemData folder and select Take Ownership from the context menu. Select yes when the User Account Control appears. Open the SystemData folder, then open the folder S-1-5-21-<string of numbers> and then the ReadOnly folder. You should now see some folders labeled LockScreen_ with a letter at the end. Open and view each folder until you find the folder with the current Spotlight picture that appears when Windows boots up. (Mine was in LockScreen_O). Move that folder with the Spotlight picture onto your desktop. (Deleting it will not move it to the Recycle Bin, it will be deleted permanently).
With that folder removed, the next step is to delete the contents of the folder used to download and store the Windows Spotlight pictures. If the contents of that folder are not deleted, the LockScreen_ folder containing the Spotlight picture that you just removed will be re-created when you logoff/shutdown the computer and the Spotlight picture will return. To get to the Windows Spotlight files, navigate to the following folder:
Delete all the files in the Asset folder. These files should be re-created if you decide to re-enable Windows Spotlight.
Restart the computer. The lock screen should now display your selected picture and not a Windows Spotlight picture. Once you’ve logged in, you can remove the “Take Ownership” option from the context menu if you don’t need it anymore. You can also delete the LockScreen_<letter> folder off your desktop.
Microsoft needs to fix this issue in a future version of Windows.