Doing so resets your Nook to factory settings, so you will lose all data saved to it. This is a standard procedure if you are selling your Nook, but if you are keeping your Nook, only do this if you are advised by a professional that you have no other option. If you are keeping your Nook, it is recommended that you back up your files before resetting to factory settings. The easiest way to do this is to download the Nook Reading App to your PC. The app will then sync with your Nook when you log into your account, thus storing your Nook Library on your PC. You can find the app in Apple's App Store, in Google Play, and in Windows Store. You cannot perform a factory reset without being connected to a Wi-Fi network. It is best to connect to a private network, but it can be done on a public network, as the information should be encrypted by Barnes and Noble's system. This will bring up the quick navigation menu from which you will navigate into your Settings. Once you are in the Settings menu, you will be able to start the process of performing the factory reset. The option to reset your Nook to factory settings is inside this sub-menu. Then, you will confirm this selection by tapping Reset Nook. At this point, your Nook should go through the process of restoring to its original factory settings. All of your settings and content will be removed from the device. This applies only if you are keeping your Nook and had to do a factory reset to resolve a software issue.

Summary:
Think about whether you truly need to do a factory reset. Connect to a Wi-Fi network. Select the Home, or 'n,' button on your Nook. Push Settings in the quick navigation bar. Tap Device Information in the Settings menu. Click Erase & Deregister Device. Register your Nook again by following the prompts that appear after it resets.