The ePub format is the digital reading standard format recommended by the IDPF (International Digital Publishing Forum). Based on XML, this format allows for dynamic paging. It is a very efficient format on portable devices such as the Sony Reader.

Requirements: follow this link http://www.adobe.com/products/digitaleditions/systemreqs/

You need to download Adobe Digital Editions to read ePub formatted ebooks. Follow this link for details of this free software: http://www.adobe.com/products/digitaleditions/

Click the start button on the Adobe Digital Editions download page and follow the instructions. The first time you run the software, Adobe will ask you to create a user account (Adobe ID). Creating an Adobe ID will only take a few minutes. This will then allow you to transfer your ebooks to other devices.

On the Adobe website, click on "Your account", top left of the page, and follow the instructions to create your Adobe ID.

When you download, the file that appears is called URLLink.acsm. Don't worry, it's normal! When the URLLink.acsm file opens in Adobe Digital Editions, it automatically starts downloading the ebook.

With Kapersky firewall: when you launch a new application, Kaspersky will generally ask you to confirm that this is a trusted application or process. It doesn't do it for Adobe Digital Editions. However, you must add Adobe Digital Editions manually to your trusted applications list. Then activate the option "Do not scan network traffic" for the application.

With SAFARI : the .acsm file will download but will not start in Adobe Digital Editions. To get around this, you must modify your Mac file com.apple.DownloadAssessment.plist.

Download Adobe Digital Editions on your new computer using your existing Adobe ID (your e-mail + password). Then return to your account and click on "My orders". You can download your ebook again.