To tweak your lock screen to your liking, select the Start button, then select Settings > Personalization > Lock screen. Then make sure Show lock screen picture on the sign-in screen is turned on. If you don't see the Windows spotlight image when you're signing in, select the Start button, then select Settings > Personalization > Lock screen. The Windows spotlight image should appear on the lock screen.

To test if Windows spotlight is working correctly, press Windows logo key + L to lock your device. Keep in mind Windows spotlight won't appear after restarting or shutting down your device-an account with spotlight turned on needs to be signed into Windows first. Check with your system administrator for more info. If you don't see the option to change the background to Windows spotlight at Settings > Personalization > Lock screen, it could be because that setting is managed by your organization. If Windows spotlight isn't working as expected, here are some things you can try:

Windows Spotlight updates daily with images from around the globe, and it also shows tips and tricks for getting the most out of Windows. Select Windows spotlight for beautiful photography to show up automatically on your lock screen. Try changing the background to a favorite photo or slide show or choose any combination of detailed and quick status notifications to show you upcoming calendar events, social network updates, and other app and system notifications.

Windows 8 slide show