For some user is the Windows 8.1 lock screen unnecessary step when you reactivate the Windows 8.1, but you can disable this quite easily!
To disable the lock screen in Windows 8.1, start the "Local Group Policy Editor"
Via the Run dialog [Windows + R] and the command gpedit.msc (... see Image-1 Arrow-1)
in the "Local Group Policy Editor" open in the tree view >> Local Computer Policy >> Computer Configuration >> Administrative Templates >> Control Panel > Personalization (... see Image-1 Arrow-2)
Now just a click on the "Do not display the lock screen" and simply Enable (... see Image-1 Arrow-3 & 4)
PS: Do not forget to press the Apply button!
... change image of Windows 8.1 lock screen!
... Auto Login in Windows-8 and 8.1 without password!
... Disable Windows 8/8.1 auto turn off!
This policy setting controls whether the lock screen appears for users.
If you enable this policy setting users that are not required to press CTRL + ALT + DEL before signing in will see their selected tile after locking their PC.
If you disable or do not configure this policy setting, users that are not required to press CTRL + ALT + DEL before signing in will see a lock screen after locking their PC. They must dismiss the lock screen using touch, the keyboard, or by dragging it with the mouse.
FAQ 170: Updated on: January 23th 2014 22:06