kimberly, how can i reset my nook u , 3rd link gives clear instruction on how to do factory fall back, just make sure nook is plugged in when doing fall back. Check the attached links,instruction and guides, Good luck.
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https://www.youtube.com/watch?v=4_Rw_kue1PQ
https://print.nookpress.com/forgot_password?email=
https://bookclubs.barnesandnoble.com/thread/14479