flash player shows as installed but will not work and is not recognized by anything including adobe

I hve installed flash player(several times) and it will not work.  programs using it tell me to install it...but it IS..I can see it in my programs list.  I have tried ev everything in adobes suggestions.  none work.  I cannnot acess my Exfintiy or any games on Facebook.  This stipid program has screwed up everything!!  All of which worked last week!!  How do I fix this?