With that said, you can resolve the problem by following the steps below: Typically, the root cause of this issue can be traced from the settings of your Adobe Reader. You might not see an error message, but a busy icon shows up for a few seconds. When files in PDF don’t open in Windows 10, something must have gone wrong when you upgraded from Windows 7 or Windows 8. Method 1: Changing your Adobe Reader settings Installed Acrobat or Adobe Reader may be damaged.PDF files which have not been created using Adobe programs.Here are some of the factors that may prevent you from opening files in Adobe Reader or Acrobat: On the other hand, PDF not opening in Windows 10 can also be caused by errors brought by an operating system upgrade. If you seem to have trouble opening PDF files on your Windows computer, it is likely that it has something to do with a recent Adobe Reader or Acrobat installation/update.