How do I get my pc window to recognize my sony prs-t2 e- reader?

Hi my name is Robert and my first time with forum.      I make sure my e-reader is connected first to my pc then I open adobe digital edition yet my reader does not appear on the program. I am able to download books to the pc application and add them to any bookshelf but that's as far as it goes. Very annoying , I looked in adobe to see if it supports sony prs-T2 and all I could find was the sony -prs T-1 for support by adobe. Yet last year I had no problem downloading book to this sony, what changed. Any help would be appreciated thanks