.NET framework has been problematic with upgrades. I have on SEVERAL machines had issues where it wanted the newer version of .NET but it frequently will not let you upgrade without starting from square one - ie. removing all of .NET versions and reinstalling. I FINALLY got my laptop to install the latest .NET by downloading the Full installation versions to disk and running the installation. I believe .NET 3.5 was the most recent version when I installed it. Once I got it installed, the installation of the other program(s) requiring it worked fine.
