Microsoft introduced lock screen in Windows 8 DP where a beautiful wallpaper appears with time, date and some icons before login, when you logout or when your PC is locked. This lock screen and User Tile can be customized, you can set custom image as lock screen background in Windows 8 here is how.
Changing Lock Screen background with a custom image
First of all copy all your favorite pictures to Sample Pictures folder “C:\Users\Public\Pictures\Sample Pictures” .
1.Now open metro Control Panel on Start Screen where Personalize section already selected on left here your current lock screen is shown with 4 sample lock screens at the bottom provided by Windows.
2. Browse for Pictures, here all pictures we added in Simple Pictures folder are displayed, select any one and click Choose Picture and you’re done.