We all know that Windows Spotlight feature in Windows 10 automatically displays fresh images on lock screen, if it is enabled. We’ve also shared the fix, in case if Windows Spotlight feature is not working for you. Here is the link to that fix:
Fix: Windows Spotlight not working in Windows 10
Now in this article, we’ll show how you can reset Windows Spotlight feature to default or factory configuration. Re-registering or resetting Windows Spotlight will be particularity useful for you, in case if fixes mentioned in above linked article couldn’t help you. In order to re-register Windows Spotlight, you need to work with few commands and you’ve Windows Spotlight at its initial configuration. Since these commands includes PowerShell version, you can easily deploy it in domain environment as well.

So here is how you can reset/re-register Windows Spotlight:
How To Re-register Windows Spotlight In Windows 10
1. Open administrative Command Prompt.
2. Type or paste the following command and press Enter key:
DEL /F /S /Q /A "%USERPROFILE%/AppData\Local\Packages\Microsoft.Windows.ContentDeliveryManager_cw5n1h2txyewy\LocalState\Assets"

3. Once the above mentioned command executed, type in another similar command and hit Enter key:
DEL /F /S /Q /A "%USERPROFILE%/AppData\Local\Packages\Microsoft.Windows.ContentDeliveryManager_cw5n1h2txyewy\Settings"

Once this command execution is successful, close Command Prompt.
4. Open Windows PowerShell and type in or paste following cmdlet and press Enter key then to execute it:
Get-AppxPackage -Name Microsoft.Windows.ContentDeliveryManager | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml" -Verbose}

Close Windows PowerShell and reboot your machine. After restarting the machine, select Windows Spotlight against Background for your Lock Screen, under Settings app. We’re pretty sure that this time Windows Spotlight will work as you expect from it.
That’s it!