How to get new download of flashplayer NPAPI to work properly?

I operate Windows 7 and use Firefox. I downloaded the  Adobe NPAPI update yesterday and now can't open any new windows and all I get are popups saying "warning unresponsive script" - continually.  The only way to stop it is to uninstall NPAPI, but then I can't access the few games I play unless I re-install. If I do, then the whole process begins again.  I have tried debugging the script" option.  Anyone have a solution?