After Many hours of fighting this, I successfully downloaded a working version of Flashplayer 11.6.602.180 from http://helpx.adobe.com/flash-player/kb/archived-flash-player-versions.html
It has many versions for operating systems, including Android. I dont know about Mac or Linux, but the windows version (about half way down the page) worked for me in IE & Firefox.
I hope this helps some of you, as I have spent almost all day on this (about 9 hours).
May I recomend that before extracting the zip file, your shoud uninstall the previous version & run Ccleaner & run Ccleaner for the registry as well then do your extraction & run the installation from there.
Good Luck, Rusty
I'm sorry you went through this. I let the installer team know how much on an inconvenience for you this was. We are working to get this bug resolved.
For others that find that the "download" button is missing, please download the installer here while we work to fix this issue:
Windows - Flash Player Installers for Windows
Why do you download the current version from the archive page? The latest installers for Windows are always available at http://helpx.adobe.com/flash-player/kb/installation-problems-flash-player-windows.html#mai n-pars_header