Calibre and Adobe Digital Editions on Windows XP

My father has an old pc with Windows XP 32 bit SP3. He would like to read ebooks on his computer, both DRM and DRM-free ebooks, so I'm going to install on his pc both Adobe Digital Editions and Calibre.

As for Calibre, if I understand correctly, I have to install version 1.48 because newer versions are not compatible with Windows XP.

As for Adobe Digital Editions, I could install one of the following versions: 2.0.1, 3.0 or 4.5.1. What version should I install? What version works best with Calibre 1.48 + the latest DeDRM plugin?

Thanks.