Looking for older versions of Adobe Digital Editions (2.0/2.5)

Hi everyone, 

I have an older Kobo which stopped allowing me to borrow library books when ADE was auto-updated to the newest version. I was told to uninstall and reinstall the older version- 2.O or 2.5. I'm struggling to figure out where to find/download the older version or if that's even possible. 

Thanks!