Reinstalling Adobe DRM problem

My wife bought a Barnes and Noble Nook some years ago

At first new books were purchased through their online  bookshop

Then Sainsburys took over the supply of e - books,

finally they transferred this to Kobo.

We managed to adapt to the change in procedures and to the new software, including Adobe DRM

My wife has a computer using Windows 10. A recent upgrade caused it to crash and required a reinstallation of the Operating System.

After this reinstallation  I was unable to locate the Adobe DRM program needed for transferring files to the Nook, so I reinstalled it.

It appears that the Adobe ID we created during the original transfer cannot be used again to activate the Adobe DRM so we are unable to download e-books to the Nook.

We have purchased several new e-books which need transferring. How do we achieve this? Do we need to create a New Adobe ID? Is there soething on the Computer we should delete so that it asks for the Adobe ID again?