What is DRM?
DRM stands for Digital Rights Management. It is a means for publishers to protect their copyrighted material in purchased eBooks. DRM prevents eBooks from being copied and distributed illegally.

HHC eBooks are copy-protected with the Adobe Content Server 4 Digital Rights Management system. Adobe eBook DRM has become an industry standard across a wide variety of booksellers and public libraries.

What do I need to be able to read HHC eBooks?
To read HHC eBooks you need a PC, Mac, or mobile device with software that supports Adobe DRM. The good news is that the software required is free. HHC eBooks can be read on both the PC and the Mac with free Adobe Digital Editions software. Many mobile devices can be used to read HHC eBooks as well. Here is a partial listing:

• IPad, iPhone, and iPod Touch: both ePubs and PDFs can be read on the iPad, iPhone, and iPod Touch with the free BlueFire Reader app.
• Android: ePubs can be read on the Android using Aldiko eReader software.
• Sony Reader: ePubs can be read with the built-in Sony Reader software.
• Kobo eReader: ePubs can be read with the built-in Kobo eReader software.
• Nook: ePubs can be read on the Nook with free Adobe Digital Editions software.
• Many Other Devices: See the complete list of supported devices. For information about reading eBooks with Adobe DRM on your particular eReader device, please consult the manufacturer’s website.

Which eBook format should I choose?
HHC eBooks are available in two formats: ePub and PDF. The ePub format has become the most universal format for eBooks. It includes many of the same features we're all familiar with on the web, like reflowable text and changeable fonts, and may be the best choice if you plan to read your eBook on a small mobile device like the iPod, or an eReader like the Sony Reader. PDF is also a widely supported format for eBooks, and it is a more visually faithful representation of the printed book. PDF format is a good choice if you plan to read your eBook on a screen at least the size of a tablet like the iPad, or any desktop or laptop computer.

Why do I get a file with the extension .acsm when I download my eBook?
When you start to download an Adobe eBook, a small file with the extension .acsm is first downloaded. This is used by Adobe Digital Editions to send the activation ID to the delivery server, which will use that ID to generate an encrypted PDF/ePub eBook, which is then downloaded to your PC. If your computer is asking you where to save the .acsm file, then your Adobe Digital Editions may not be installed correctly or not yet authorized. Often you can solve this issue by simply setting your computer to always use Adobe Digital Editions to open this type of file.

Why do I have to activate/authorize my reader?
Because HHC eBooks have built in security in order to protect their copyright, you may be required to activate your software before downloading, to identify that you are the rightful owner of the eBook. In the case of Adobe Digital Editions software, you can opt not to authorize the software, but if you do this you will not be able to transfer the eBook(s) to other devices you own, and in the event of having to reinstall Digital Editions, it may not be able to open your existing eBook(s). To ensure full access to your eBooks, it is best to authorize your computer or device through Adobe, by obtaining an Adobe ID and entering this when you first set up Digital Editions.