Windows Live Mail will install on Win10 but requires Net Framework 3.5.  When trying to install this from the installation prompt, the browser window for the download greyed out.

To be able to download NET Framework 3.5 it was necessary to go to:

Control Panel -->Programs --> Turn Windows features on or off --> Dot the option:  NET Framework 3.5 (includes Net 2 & 3)

Windows Live Mail then installed and runs fine.