Moving this discussion to the Adobe Digital Editions forum.
Janeyred what exactly are you being prompted to upgrade?
Microsoft .net framework 3.5 SP1
If you go to Programs and Features what version of the Microsoft .Net framework does it indicate you have installed? Have you tried repairing or removing and reinstalling your current .Net framework installations?
Was this computer upgraded to Windows 8? If so which operating system were you using previously?
I noticed that there is a place for me to turn on 3.5 so I did and that
seemed to work.
Thanks for getting me to the right place to find that.