Follow these steps to backup ebooks: 1  Download the Kindle app for Windows or Mac. 2  Open the app and sign in with your Amazon account. 3  You'll see all your books listed in the app. Right-click any book and click Download.  To make a backup, you just need to copy the folder Amazon has saved the book in. On Windows 8, you'll find the books in C:\Users\yourusername\AppData\Local\Amazon\Kindle\application\content. Windows XP, Vista and 7 need to go to C:\Users\yourusername\Documents\My Kindle Content.