Unable to open Adobe books

Question

I have 4 books purchased many many years back and the computer I initially had them on long ago died as a XP machine.
I can not access any of the 4 that were purchased and Adobe Digital Editions refuses to open and Acrobat will not open indicating DRM issues.
How can I have this fixed????

Answer 1

When you say ctrl-shift-D didn't work what do you mean?
Do you mean
it didn't have any effect and nothing happened.  No prompts asking about confirm remove authorization, no nothing
or do you mean that ctrl-shift-D did do the deregistration,
you went through the complete deregistration/reregistration process,
but the result was the same as before.
~~~
Some vendors use the standard Adobe ID, some use their own custom vendor ID.
Maybe the book is one that needs a custom vendor ID?
Check that with the vendor to see what for their ID should take.
I haven't used any such books, the Adobe help (http://www.adobe.com/uk/products/digital-editions/features.html) says
Custom User ID (Vendor ID, Bookseller ID)
When you open a book requiring alternate authentication, you will be prompted to select which ID and provide credentials (user name and password). You may, for example access a book from Google with a Google ID (referred to as a Vendor ID), or a book from Barnes & Noble (referred to as Bookseller ID). This is further described in the Getting Started eBook installed with Adobe Digital Editions.