Win8.1 itunes64setup refuses to complete download. WHY!?

The auto update hangs ... so I try to download the latest version. Before I can set the directory to which the download should save I get the "Thank you for downloading iTunes" screen and no download! I back-track a page to try the downlaod again. This time I quickly quickly accept save to whatever directory is current and the download starts. BUT IT ALWAYS HANGS after a few meg. The most I've got is 21mb, more usually 8 or 9 Mb.

I am cheesed off with this update process - can anyone tell me how to perform a download of the software without having to restart it endless times! Or is there a more reliable bit of software I can substitute.

I'm on Win8.1 64bit using Mozilla Firefox trying to downlaod itunes64setup.exe