The easy solution would be keeping my Adobe Standard as my default PDF program while using NitroPDF to preview my PDF documents. I loaded the free version of NitroPDF that fixed my PDF Preview issue but it switched my default PDF program along with it. I installed all updates to keep my version up-to-date, and even tried to uninstall and reinstall. It kept throwing out the “ WerFault.exe – Application Error” every time when I highlighted a PDF file in my Windows Explorer with Preview Pane turned on. My default PDF Previewer, Adobe Standard XI, stopped working the other day.