I have Adobe and Acrobat. I tried some of the suggested answers. In right clicking on PDF and clicking on open - screen pulls up Windows 7 Word - and a gray square appears titled "File Conversion" and lists different OS to choose. when choosing Windows a list shows to the right offering may different languages to choose from - closed I see to English is Western European - but preview screen shows that with that - document appears in some kind of computer language. Never used to have this problem - used to click a PDF to open and it did. Suggestions?