About one week ago I determined I could no longer open pdf documents with my Adobe reader software. Worse than that, I couldn't delete the version I had and start over. When I downloaded a new version, it wouldn't install because the old version was there. I was more than frustrated for a couple of days. Then I found a message about Foxit Reader and installed that and I was back in business.
Yesterday at work I encountered the same problem and quickly downloaded Foxit reader and was back into business. Last night on the news I heard the problems I encountered are widespead. So if trouble comes to you, google Foxit Reader, install it, and you'll be back in business with pdf documents in about five minutes. Good luck!