What means "unable"; what happens when you try?
[topic moved to Flash Player forum]
I am able to download it and it says that it has been installed and tells me to restart any open browsers then when I go to view something that requires adobe flash player it says that adobe flasher player is required to view this and to follow steps to install it. I follow the steps and the same thing happens.
In Safari, click Help and then click Installed Plug-ins.
Do you see Shockwave Flash displayed there?
If not, click Safari > Preference > Security.