You do not need an Adobe ID, however we encourage all new eBook users to register for one. If you register for an Adobe ID you will be able to re-download, or access your eBook on multiple devices. Your eBook and all future eBooks you download will be associated with your Adobe ID for easy file management.
Important: If you authorize your computer with an Adobe ID, then it will always be associated with that Adobe ID. If you do not, the account is "anonymous". If you "anonymously" activate two computers, then there are two separate anonymous accounts, which cannot be merged. Thus, the eBooks on one computer can be upgraded to "belong" to a specific Adobe ID, but the eBooks on the other cannot. If you authorize the second computer with your Adobe ID, any subsequent purchases on it are associated with that ID and transferable to any computer authorized with that ID. However, the books that were purchased on the second computer prior to being activated are forever locked to that computer.
Digital Editions has an “Authorize this computer” menu item that you can use after initial installation if you register for an Adobe ID after you've downloaded your software.
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