how to download to Kobo Reader when you also have a Sony reader?

I have both a Kobo Reader and Sony reader, which was taken over by Kobo. I have both Adobe Digital Editions 3.1 and Reader for PC software on my PC laptop. Whenever I try to download an EPub from my local library onto my Kobo, it automatically does it in Reader for PC which only works for  the Sony, and I can never get Adobe Digital Editions to kick in and transfer the book to my Kobo. Does anyone have a solution to this problem? Peter