Just received: Dear Customer,

Thank you for your inquiry.

We do apologize for the inconvenience we ask you follow the steps
provided to fix the issue.

Sign out and close the application.

Under control panel go to folder options and click the radio node to
Show Hidden Files and Folders.

Granted your using Windows Xp - Navigate to C:\Documents and
Settings\USER NAME\Application Data

If your using Windows Vista or 7 - Navigate to C:\Users\USER
NAME\AppData\Roaming

Delete the Barnes and Noble Folder.

Launch the program and register successfully.

This is why we all bought nooks! Every once in a while we have trouble but a far better ereader experience than I've had on my other devices. Even their iphone app is suck-ish.