Howtogeek posted a tutorial about customizing the Windows 8 lock screen

Windows 8’s lock screen is very at home on a tablet, but it can also be used on laptops and desktops. The lock screen is not just a background image – it contains widgets that display quick notifications.

These widgets, known as lock screen apps, allow you to view information – such as new emails, weather, calendar appointments, instant messages or social updates – without even unlocking your PC.

  How to Customize the Lock Screen on Windows 8