Hi! I have a similar poblem. I tried to authorize the computer using my Adobe ID that I also use for my Kobo ereader. I am told that I cannot authorize my computer using an ID of another device. If I download an ebook protected by DRM, I am able to read it on my computer, because it seems that I can use Adobe ID on my computer without linking it to a specific ID, but in this way I cannot download it on my ereader because I use up the licence that the ebook's seller has provided. In fact, the e-reader tells me that the book has already been dowloaded by another user.
Is there a way to undertsand how my computer is working with Adobe, which ID it is using and why I cannot link it to the ID I use for my e-reader?
An additional issue with my computer, is that if I connect my e-reader, my computer no longer recognizes my e-reader. These issues started after I upgraded to Windows 10.