Once you've finished doodling your new password, you should be ready to rock. Window 8 defaults to the picture password anytime the system is locked or restarted, and ideally all you have to do is draw your gestures on screen to unlock the system.
If you want to switch gears and input your plaintext password instead, just tap the corresponding button in the left pane of the picture password screen. You should also be aware that picture password logins can be disabled from within the Windows 8 group policy editor; many businesses do not allow picture passwords to be used on networked machines for security reasons, so be prepared for that if you plan to bring your Windows 8 device to work.
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