I can't install the latest version of flash player

About a month ago I wiped my hard drive and reinstalled everything. When I tried to install the latest version of flash player nothing would happen when I clicked on the downloaded file. I was able to install a slightly older version (20.0.0.235) and when the auto update for version 20.0.0.286 arrived it installed just fine. I just don't understand why I can't get the latest version to install when I go to this site Adobe Flash Player Install for all versions

I'm using Win XP Pro SP2, Firefox 25

Thanks