I have tried EVERYTHING. (Except what must work.) So if you are going to tell me to disable stuff, or to lower my security to the bottom, done that, been there.
Right click any of the following links and "Save as":
Those are FULL installers. They don't need to downbload anything else to install. They don't need a connection to install, once downloaded.
If they won't download that way, you've got connection or firewall problems we can't help, and I suggest downloading from either of those links to a Flash drive from a different system at a different location,