IF your Kindle is a Fire(at least 2nd generation), you should be able to a factory reset from here (www.amazon.com/myk). Go to My Account > Manage you content and Devices and click on the device tab. If it is available, you'll see REMOTE FACTORY RESET as an option in the drop down menu under DEVICE ACTIONS. Please note: The Fire’s battery needs to be charged to at least 30% and it must be connected to a Wi-Fi network. If this doesn't work, or of the option is not available for your Kindle, please let me know. Thank you!
After resetting the Kindle, just make sure when you set it back up that you use the same Amazon email address and password ***** you are currently using. After setting up the Kindle, please login to your account at Amazon.com. Select YOUR ACCOUNT. From the drop down menu that appears, please select MANAGE YOUR DEVICES AND CONTENT. On the page that appears next, you will see a CONTENT Tab and a DEVICES Tab. On the CONTENT tab you will see all of your Kindle book purchases. You can sort them by title, author or purchase date. Please locate the book that you want to download to your Kindle, select it by checking it and then click on the ACTIONS column. Choose deliver as the action. Select your device from the Device list. If you have more than one Kindle, make sure that you choose the Kindle that you are actively using. Don't select the Kindle Cloud reader unless you have downloaded the Kindle Cloud Reader APP to a computer or device other than your Kindle and wish to read it there.
Please give this a try and let me know how it works for you. If this solves the problem., would you mind taking a moment to rate my service? I'd really appreciate it! Without a rating I am not credited for my answer. If you need more help, please let me know so we can continue troubleshooting. please tell me exact model of your Kindle. If you're not sure, please look for a serial number. If you can't find it on the Kindle, you can find it on the Manage Your Kindle page of your Amazon account (in the Manage Your Devices section).