Hi

I bought a book in PDF and can read it on my pc and download it to the Cybook but every time I try to open it on the Cybook I get an error code. I have tried registering the cybook with MS Passport but it won't register the device saying it doesn't have adobe reader on it. Any advice?

If you mean you purchased a commercial PDF book then likely you won't be able to read it on anything but your PC. Your Cybook will read PDF's, but not PDF's with DRM.