The Barnes & Noble Nook and Nook Color may freeze during normal use, making the controls unresponsive and prevent the screen from turning off. You need to perform a soft reset on the e-readers when they freeze to regain functionality. Performing a soft reset on a Nook or Nook Color is similar to rebooting a computer. Your books and other files are not lost during a soft reset.
Connect the power adapter to the Nook and plug the other end of the adapter into an electrical outlet.
Hold the "Power" button on the left side of the Nook until the device shuts off, which takes approximately 20 seconds. A prompt appears while holding the button with an option to shut off the Nook. Ignore the prompt and continue to hold the button until the Nook turns off. Release the button when the Nook shuts off.
Push and hold the "Power" button until the Nook turns on, which takes approximately 3 seconds, to complete the soft reset.