Maybe the behavior will be different if you use the full (offline) installers.
Adobe Reader: http://get.adobe.com/reader/enterprise/
Flash Player: http://helpx.adobe.com/flash-player/kb/installation-problems-flash-pla yer-windows.html#main-pars_header (under the header Progress Bar Hangs)
If this also fails: is your system language set to something else than English? I have set my system language to Japanese (on English Windows), and many programs react by displaying only Japanese dialogs.